Using Epoxy to Fix Porch Wood Railing

In my previous post, How To Repair Porch Railings, I showed you how you can cut new wooden spindles with a subtle angle to allow water to drain from the wood bottom rails of both upper details and porch railings. Read on to learn how to improve long term rot-resistance by adding epoxy products to your home repair toolkit.

 

Part I: Epoxy

Since the upper accent rails (and/or hand rails) are disassembled and unpainted, why not make the extra effort before reassembly to protect the end grain that we know wicks moisture into the wood and leads to rot. In fact, the process is pretty simple and fairly quick.

When applying epoxy to cut spindles, I use a throwaway chip brush and container.

Rot Fix by System Three is the product I've gone to again and again, around the house exterior where rot always seems to be creeping up. So what is Rot Fix? It's a two part epoxy that is low odor, has a simple 1:2 mix ratio with a smidge of tolerance for not quite 1:2, and has more open time the cooler the workspace is. I wouldn't recommend using it below 50 degrees (although I have), unless the piece can be moved into warmer surroundings. Higher temperatures ensure a quick cure of the mixed parts. If I wanted to get on with the project, I would put the piece in the greenhouse to speed up the cure!

Let me be clear, a two part epoxy requires some accuracy —don't go eyeballing the mix ratio until you've had plenty of experience with it. I use cheap, translucent plastic cups as my measue and mix cups. The hardener/mix cup is marked at X level —this will be the 1-part volume of amber-colored hardener. This amount can be whatever you want! Just be aware that your final mix will have three times the volume as you add 2-parts of the clear resin to the mix cup already filled with 1-part amber hardener.

Why do I use the hardener cup as the mix cup? Because the clear resin is much more fluid than the hardener. Both components will stick to the sides of the cup as you pour one into the other, but the clear resin is much more fluid and less likely to lose significant volume in the process. If you wish, take the "grip" of the resin into consideration and add into the resin cup a drop or two above your mark. Rot Fix is fairly tolerant of slightly-off ratios, as long as it is only a drop or two!

What happens if I mess up the ratios? I've had it happen, once. For me, it was not enough hardener and the epoxy never fully cured —it will be sticky, well beyond the normal cure time of 12-36 hours (this is dependent on the temperature where you work). I replaced the piece with another and the next epoxy batch was fine. That mishap never happened again. Too much hardener and your mix will cure and likely be brittle. Epoxy depends on the chemical interaction between two parts and a good result depends on simple measurement. I trust that if someone is willing to repair their railings, they are capable of using Rot Fix successfully.

Bottom rail with Rot Fix applied to end grain. Scuff-sand to take any primer

Any end grain, new or old, can benefit from Rot Fix epoxy. It is fluid enough to be absorbed by the pores in the cedar. Sealing the ends limits moisture wicking into the railing. and is a little added protection against future rot. 

I must point out, however, that this isn't something you would do to wood you plan on keeping unpainted. Rot Fix does not have UV stabilizers to protect it from breaking down in the sun. Exterior paint has UV absorbers and pigments that protect the epoxy and the wood from UV breakdown. Therefore, anything you Rot Fix must also be painted. The finish of Rot Fix can be slick, so I like to scuff it with a 180-220 grit sandpaper before priming. However, there have been a time or two where I've used Extreme Bond primer, by Sherwin Williams, because it is really good at sticking to slick. But my general practice is to scuff sand epoxy before priming.

Part II: Restoring Beat Up Rails 

 

System Three SculpWood is a much better repair material than any box store wood fillers.

The reality of removing/dismantling railings is that there can plenty of nail holes, screw holes, slivers of missing wood, splits and even carved out rot. Finding a new piece of matching rail is often out of the question for older railing systems. Enter System Three Sculpwood —an epoxy putty that is easy to mix with 1:1 ratio, no odor, doesn't sag, and can be shaped and sanded. I use Sculpwood in combination with Rot Fix to bring that beat up old railing back to life. How?

 

First, I apply Rot Fix to the area that needs to be filled. Depending on how much time I have, I can allow it to fully cure before filling with Sculpwood, or I can begin filling after only a partial cure of Rot Fix. Either way, both products will bond to each other, but my preferred method is to start filling before full cure. Sometimes I seal the entire patch with more Rot Fix after the Sculpwood filler has been sanded smooth. I'm into overkill when time allows.

 

Holes can be filled with Sculpwood Putty, smoothed with a putty knife, then sanded.

Mixing Sculpwood is easy. Its moist flour-like consistency allow me to approximate the needed chunk of white resin and cocoa hardener. I then roll these chunks into balls to eyeball the 1:1 ratio of resin to hardener. If one ball is a bit smaller, simply add more to it. When these two balls are mixed, they become a consistent blend of the two colors. I use these nitrile gloves when mixing any epoxy, but especially when rolling balls of Sculpwood. 

This combination of epoxy liquid and putty, after proper curing, is extremely tough, grips wood with tenacity, can be sanded easily, and then painted like any other wood. Yet, sometimes the rail is too far gone, or you have some scrappy pieces of bottom rail left from, say, the replaced back landing, that match. What can you do? 

Epoxy to the rescue. It is possible to combine two smaller pieces of rail with a scarf-joint glued up with Rot Fix. Cut two rail pieces with a miter, say 45 degrees, making sure that they are cut so that they match up in the way a scarf-joint requires (see pic, below). Apply Rot Fix liberally to the two miter-cut ends and bring the pieces together. Hold together tightly for a minute or two. It is hard to clamp such joints, especially with wet epoxy all over, so I use a three well placed brad nails sunk into the just epoxied joint. 

The piece imagined as a scarf-jointed assembly with epoxy and brads.

When I am certain the two pieces are firmly together, I apply more Rot Fix across the seam of the scarf joint and onto surrounding wood. You'd be surprised at the strength of this union after the epoxy has fully cured. Just make sure not to bump it or move it while curing and keep the pieces elevated so the epoxy does not glue the rail to the table! 

 

When the the second round of Rot Fix is partially cured and the two joined pieces feel like one, you can then use Sculpwood to fill in big gaps —if there are any. This procedure is better for bottom rails than handrails, although I have done both. Your mileage will vary with handrails exposed to weather and sun. Unfortunately, I do not have any photos of the handrails I scarfed this way.

I am certain one or two of the rails on this table had been scarfed together with epoxy.

 

Reassembly

 

Make sure to pair up the right-sized bottom rail and top board.

If you have taken down several sections of railings, its a good idea to match 2x4 lengths with bottom rail lengths to ensure the rebuild goes smoothly. Because putty work, sanding and paint can conceal the original spindle placement, you can use the screw holes in the 2x4 top boards to space spindles. Or you can measure railing that is still mounted to the porch and take that as the basis for spindle spacing. I think these had roughly 4.5 inches between each spindle, or roughly 6 inches on center. 

 

Pro Tip: Remember that the two end spindles need to attach to posts, so they need to be at the ends of the rail no matter what the spacing. It won't come out perfectly spaced, but most eyes cannot see 3/8ths of an inch across all these spindles.

Bevel cuts must be on the bottom rail, pointing outward, any way you assemble them.

 

To Paint or Not To Paint —Before Assembly

 

Spindles are easy to prime after the Rot Fix epoxy has cured on the bevel-cut bottoms. However, for purposes of illustration, I left some spindles unprimed to make its easier to see fitment in the photos. The top 2x4 cedar pieces required no repair, so received primer ahead of reassembly. Milled cedar pieces, like the bottom rails (on top, in the image above), received Rot Fix on ends, holes were filled with putty, then were sanded and primed. 

 

Why prime, but not paint? It's perfectly reasonable to paint each component before attaching. The spindles, however, I avoid painting because quickly applying glossy paint leads to build up on the ends, making attachment more difficult. Primer is a lot thinner and causes no issues with attachment. More about paint, later.

Had a Senco PC0947 tank & FP18 gun for 18 years, but just sold the tank & got a Rolair.

 

Necessary Tools

 

You can manage reassembly with only a hammer and a drill, but it's quicker and better looking when a pneumatic nail gun and drill are used. A drill can drive screws, but I prefer an impact driver for driving screws. 

 

Compressor, Tank & Guns 

I bought my Senco hot dog compressor and 18G nail gun kit from Amazon, for $199, in 2006 —hard to believe you can still buy it, although the gun seems to be red, now. After 15 years, the quick connect valve began to leak, so I sold the tank this summer and kept the gun. That old hot dog model has been succeeded by the Senco 1010, with the same 1/2 HP, 1 Gal tank rating, which you can also purchase on Amazon, here. It appears the brad guns are sold separately now, but I believe the successor model also accepts 5/8" to 2" 18G brads like the FP18, but I cannot speak to its quality. I still use the original FP18 with little troubles after 18 years, but now with a new tank and compressor.

 

There are many brands and models of nail guns and compressor/tanks out there. There is no need to match the gun brand to the tank brand. I spent way too much time losing hearing to Dewalt and Craftsman pancake models in the 2000s, so I was excited to find my current compressor/tank, the Rolair JC10, on Amazon, in 2020. Previously, this brand was only available from an exclusive distributor network and not easily found in my area. The Rolair has double the HP, 2.5 times larger tank, and is 10 decibels quieter than the Senco. It is more costly, heavier and a bit larger, but I love it for its low decibels (and the green color). It works great with my 18 year old Senco FP18 and with a larger tank, is even quieter because it won't kick on as much as a 1 gallon tank.

The handy Dewalt Max XR Impact Driver

Drills & Drivers

As I stated earlier, you can complete this project with only a drill, but I prefer a separate drill and impact driver. In the early days, when I was first learning to drive screws into decking, we used drills. After pre-drilling the deck boards, Phillips heads were constantly stripped out while driving them into dense, treated lumber below. An impact driver and star-drive screw eliminates this.

I have been enjoying my Dewalt Max XR Impact Driver since 2020 and will never look back. I wish I had bought it sooner! My drill is a Dewalt 1/2 inch, model DW780, which I believe is now out of production. The strongest replacement for it would be the Dewalt DCD800 which is on Amazon at a low price right now. Another drill, for someone not needing as much power or as many metal parts, is also at a good price right now —the Dewalt DCD771.

Fasteners

For a decade, or more, I had to hunt for star-drive screws. Then there was the awful period where square-drive screws became commonly available, but these always stripped out before sinking into treated lumber, sometimes even much softer cedar. Thankfully, star-drive has finally become common at most box stores and you have a lot of choice now. 

 

I prefer to use two brads to attach the bottom rail to each upper accent spindle. For this I use 2 inch 18G galvanized, such as these. No splitting, small heads and holes are the reason. However, if you choose screws, use outdoor rated, trim head screws like these GRK #8 x 2 star-drive, stainless steel trim screws. It's okay to use epoxy coated to save, however, stainless is just a little added protection. The trim head keeps the holes small. I recommend pre-drilling if you find your spindles split from driving screws. Screws driven closer to spindle center, are much less likely to split.

 

To attach the upper accent's 2x4 to each spindle, I recommend outdoor rated, #8 x 2 or 2-1/2 inch screws like these. Same advice as above if you find your spindles splitting. To attach a length of reassembled accent to porch roof beams, go with outdoor rated, #9 x 2-1/2 inch screws like these. To attach the two side spindles to posts, use the trim screws suggested above or lower cost Power Pro, like these. For attaching a length of balustrade, aka the handrail, spindles, and bottom rail unit, use outdoor rated, #9 x 3 inch screws like these Power Pro.

 

Two brads sunk through the rail & a screw through the 2x4 to attach each spindle

Interior carpenters know that a nail is just a clamp holding things together while the glue dries. But in outdoor carpentry, this isn't usually the case. We depend on outdoor rated screws for most fastening, although there are instances when screws are not palatable or practical. At these times, we rely on galvanized brads.

Pro Tip: Be careful with aiming so that each brad lands within wood. If you have one bend and shoot out the side, you can pull it out or cut it —either will cause a bit of damage, but won't ruin the project.

To attach the bottom rail to the spindle's bevel-cut side (keep repeating this), I use one 2 inch galvanized brad to fasten the bottom rail to the spindles. This single brad is holds the spindles in place before I sink the more functional, angled brad. This second 2 inch brad is driven through the angled side of the bottom rail into the spindle to give the piece a measure of downward-pull resistance.These accent rails are fairly light weight, so the issue is people hanging plants or other heavy objects from them. If this is a great concern, go ahead and drive 2-1/2 inch trim screws to attach the lower rail to the spindle. 

 

After the bottom rail is attached to the spindles, flip the unit 90 or 180 degrees to drive screws through the 2x4 into the spindle. Consider pre-drilling through the 2x4 for well-targeted, straight driving. 

 

Pro Tip: Use two bar clamps to hold the entire unit together while driving screws. Ensure that the spindles are all spaced properly and are square as possible. Place a piece of scrap between the metal of the clamp and the bottom rail to protect it. No need to clamp super tight —the clamps are more like another set of hands.

Once the entire unit is assembled, it's either time to install or time to paint. If the unit isn't primed already, consider using Sculpwood to fill brad or screw holes. If the unit is already primed, there are several exterior wood filler products that will stick to primer, like this one from DAP. If the holes are not significant, you might simply do what the original builder did —just paint right over those brad and screw holes. This is a matter of how detail oriented you are.

Paint

We all have paint preferences, but whatever you use, do not buy the lowest cost paint.

 

I've been using Sherwin Williams paint, for outdoor projects, over the last 8 years. I was a big fan of their Resilience line, in satin or gloss, because of the excessive or surprise rainfall we were getting during this project and others. It came at a lower cost than their top of the line Emerald and had the same application temperatures —down to the 40 degree range. It's best feature was the early wet time: it can get wet after four hours of drying time and proved itself time and again. Unfortunately, the Resilience line has been replaced by the Latitude line which, according to counter person, has improved features including the same early wet time. 

 

Pro Tip 1: Do not expect new, same manufacturer but different line, colors to match old colors. You will need to get a tester pint/quart to check for a match or simply repaint the entire porch with the new color. 

Pro Tip 2: If you are shopping Sherwin Williams, only buy paint when they have their homeowner 30-35% Off coupon sales. It happens several times a year and, in my opinion, reflects the true cost of the paint. Make sure your paint line is covered by the sale.

Pro Tip 3: I prefer gloss for porch railings -its tougher and I believe it is better at shedding water and for cleaning all the dirt from our country roads and farms. I use satin finish for trim and siding. I think matte looks nice, but is a mistake for the sake of longevity and cleaning. Resilience paint I've applied a decade ago on 30 year old LP siding and cedar trim still looks great.

Addendum:

I mentioned that it is possible to use the very same techniques on the handrail as on my example upper accent porch trim. Therefore, I have added a few images of the handrail as there are some minor differences.

People lean and put feet on balustrades, so screws are used to hold on the bottom rail.

As you can see in the above image, there is a screw sticking up through the bottom rail of the balustrade. Screws were used to fasten the spindles from below  —opposite the technique of the upper accent rail covered in the above article. Why?

Porch balustrades take a lot more abuse than upper accents. When someone leans on a handrail, they often place their foot, and body weight, on the lower rail. This requires the greater holding power of screws. Fortunately, a balustrade has several spindles with screws allowing the unit to resist that downward pressure. 

 

Pro Tip: When dismantling a balustrade for repair or restoration, some of these screws may spin in place, instead of back out. Try to get them out without too much damage. If any screw remains, it will interfere with the new screw, so it must all be removed. If they cannot be removed by hammering it through, consider using your Fein Oscillating Tool to cut it. 

 

Screws on underside of the balustrade lower rail must be removed to reuse the piece.

Of course, the underside of the bottom rail is not visible, so screws are a good choice there. To reuse this piece, the entirety will need to be sanded to remove paint and slivers of cedar. If there is no active decay, I would use my Rot Fix to seal the whole piece, then fill the screw holes with Sculpwood. 

 

These balustrade bottom rails and the bottoms of the spindles, especially on the sides and corners of porches, are more likely to have been rotted or have active decay. Look for rot near end grain and where screws or nails penetrate anywhere on the balustrade. The rot needs to be treated and crumbly spots carved out, then epoxy used before installing the unit back onto the porch.

 

Pro Tip: Rot Fix is a great product, but it will not kill or contain fungus that eats wood for lunch. What I do is use the fungicide boron —a naturally occurring mineral. The product I use is called Tim-bor, which is a professional grade, water soluble crystalline powder (use a dust mask!) that can penetrate wood pores. After a couple of wet applications to old or new wood, let it dry (where applied, you'll see a translucent, light gray haziness). Then apply Rot Fix and Sculpwood. The product can be found on Amazon, under the brand Nisus.

Exposed handrail can be beat up, especially at porch corners or around brad nails

As a large piece of complex millwork, the handrail is the most expensive component of the balustrade. If you cannot find the same profile, new, or even if you can, but need to reduce costs, you will want to save as much handrail as possible. You'll usually find the best-condition handrail under the porch overhang, especially if it only receives morning or afternoon sun. Be thankful if you found it in good shape!

Porch corners, as well as the sides of a porch, however, will be exposed to excess moisture and sun. This makes these locations prone to more moisture, UV breakdown, expansion and contraction. Upper accents, siding and roof shingles continue to drip all their moisture onto these exposed balustrade sections, so they will be in the poorest shape.

The handrail is brad-nailed into the spindles —sometimes from both sides, sometimes from only one side, sometimes with two brads on one side. These decisions were made by carpenters or their helpers. It may be reasonable to conclude that nails on the exposed side of the handrail invite problems. On the other hand, we may think the handrail will be more firmly attached if nails are sunk on both sides. What is best? Hmm. 

I know this: when pneumatically driving a long brad through one side of a handrail into a 1.5 x 1.5 inch wide spindle, there is plenty of chance for that brad to hit the other brad driven from the opposite side, bend it, and send it somewhere you never intended (hopefully not your finger).

Pro Tip: Use the shortest brads that can do the job. This may be 1-1/2 inch brads, although it depends on the profile of the handrail. My solution is to drive double brads, like in the photo above, but alternating the side as you go down the handrail. This ensures a firmer connection to the spindles, yet removes the chance of bending, haywire brads. 

At the bottom of the handrail there is a channel where the spindle top resides, so that each brad acts to lock the spindle in place more than provide a super-strong structural connection. Consider that gravity is doing some of the work, too, as handrails rarely receive much uplift pressure. Where ever strength is required in outdoor woodwork, you will find screws, real nails, lags, bolts, or some old-fashioned wood joinery. Wherever limited structural strength is required, or impractical, and the fastener would be unsightly, you will find brads.

All said and done. Notice a post was removed when I replaced the old side staircase.

Restored balustrade and accents, stair case (don't ask about those lattice!)

*Please note that the tools and products in this post are the one's I actually use, and if I link to a different product, it is only because it is a successor model to mine. 

 

Since 2007, this blog has provided valuable information and entertainment without the use of ads or any other commercial enterprise. As of January 1, 2025, some of my blog posts will have links to products that I have personally used and found helpful for completing projects. I would not suggest, nor link to, a product that I did not find helpful, useful, or otherwise high quality for its intended purpose. If you have found a post helpful and would like to purchase a suggested tool, book, or other product, please consider clicking through the Amazon Affiliate linked product. If you do, you will support the creation of even more informative posts. Thank you! This post contains links to Amazon: As an Amazon Associate, I earn from qualifying purchases. 

Repairing Outdoor Wood Railings

Our house has been undergoing many exterior repairs over the last dozen years, including new doors, rotted sill replacement, window-frame rot fixes, replacement decking, siding replacement, new stairways, new paint and plenty more. Some of these repairs were necessitated because the builders did not stick with good-sense carpentry (door sills level with uncovered decking), some are from manufacturer defects (windows), and others are simply due to the climactic extremes we have in Minnesota (-35F to 100F, 20% RH to 99% RH).

New front staircase: more steps, lower rise, reused wood, and retail railings.

I began working on this porch in 2013, when I replaced the main staircase that was made from stock stringers with too few steps for the total rise. Over the following years, I could see that the porch railing was failing where exposed to the elements and needed reconditioning where partially exposed. Professional porch repair can get expensive fast, and results can vary. You may find the contractor using treated wood where you wanted cedar, or the style of railing may no longer be commonly available. Add to this cost the next job, porch painting, and costs may become downright prohibitive. This is where you step in to figure out how to repair it yourself. Fortunately, with a few simple products, you can fix rotten spindles, bottom rails, and expensive top rails, without too much skill or effort.

Before plastics and treated wood became common porch construction materials, many mid to late 20th century porches were made with Western Red Cedar —a naturally warp and rot resistant (not rot proof) wood grown in North America. This is what our porch rail posts, spindles and bottom rails were constructed with. I believe the handrails were made from Douglas Fir. 

 

Porch railings are often constructed by quick-moving builders who do not have time to make the little adjustments that will allow rain, snow melt, and dew to drain from bottom rails. Water standing for any period of time on paint and wood will eventually lead to decomposition of both materials. The railing repaired in this post is about twenty-five years old, a little older than the amount of time I would expect above ground, partially-roofed cedar to last in our moist environment. However, the fully exposed railings on stairs and uncovered decks were partially or fully-rotted by the 20-year mark.

 

The porch railings to be repaired —from this distance, all looks well!

 

Below I will go over techniques for repairing the upper accent rail seen in the above picture. These same techniques can be used to address the spindles, lower rails, and possibly the handrail. If you have a porch built before 1940s, porch woodwork can be more ornate than what we see on houses built from the 1980s onward, which tend to have simple square spindles and few decorative embellishments. Older homes can be repaired using similar techniques to those I describe below, so read on if you intend to work on an older home's porch.

The Problem

 

Decay is usually found near the bottom. Here, where the spindle meets the lower rail.

 

Wood placed against wood will hold moisture and eventually decay, even when painted. In fact, the rotting wood will undermine the surface coating leading to paint failure which you will notice first. Rotted wood is soft, sometimes crumbly, sometimes green with algae, and sometimes even releases moisture when pressed. This is most likely where spindles meet the bottom rail, particularly at porch corners, where they receive rain from two sides. The spindle's end grain wicks up moisture into the wood.

 

Another common location for rot: where the bottom rail meets a post.

 

Another prime spot for decay is the bottom rail ends, particularly at the porch corners. Water running down the porch corner posts and spindles collects at the bottom rail. The rail's end grain wicks moisture into it and the spindle also wicks moisture up into itself, holding moisture against the bottom rail. Nails or screws driven from the underside of the bottom rail, up into the spindle, helps to bring moisture into the spindle and lower rail.

Accent rails and spindles at the top of the porch

 

Top accents at the front of a porch don't see much rain thanks to the overhang, but porch side accents see sun and rain on the south side and, on the north side, may never dry out for lack of sun. Both conditions lead to rot. Although it's commonly understood that a shady, damp north side of a house can rot, it's surprising to hear that a full day of sun can also lead to decay. This is caused by greater exposure to UV rays, more expansion and contraction, as well as moisture. 

Accent rails that have been repaired, primed, and are awaiting new spindles

 

The Tutorial

 

This tutorial will show you how to fix porch railing rot using the accent rails as an example. The process for fixing the lower railing is exactly the same as the upper accent pieces —only with longer spindles. If the handrails have rotted, this is another matter entirely. It is often difficult to source matching handrails for older porches. You can have new lengths milled, at a cost. Alternatively, you may choose to replace all the handrails, at once, with a new profile. Another option is to try to repair the handrail, piecemeal —I've certainly done this, to greater and lesser success. I will need discuss that in another post. 

First Steps

The first step is to take your accent rails down. On homes built before 2010, these rails are typically installed using phillips head screws driven up into the porch roof framing. First and last spindles are sometimes attached with finish nails or phillips screws into porch posts. These should all be fairly easy to remove. If nails are used, or screws spin but do not come out, you can use a small pry bar -but this can do some damage. Its better to use a tool like the one shown below to cut nails or embedded screws that spin, but don't come out.

My Fein Multimaster 350Q is now out of production.

 

The Feintool Multimaster oscillating tool is my home repair go to power tool. If you do any kind of work where tight space, flush and low-impact cutting/sanding/more is demanded —you didn't know you needed it until you have it at your disposal. There are lower cost brands, of course, but my Feintool 350Q hasn't let me down yet. I believe the Feintool 500MM is the successor model to the 350Q.

 

You can use the Fein metal-cutting blade (see pic, below) to slice through hidden nails and common screws. However, be aware that hard screws will wear your blades faster than nails will. Blades are the expensive part of a Feintool Multimaster. There are cheaper options, in blades and oscillating tools, but you pay with usability and longevity when you take the lower cost route —ask me how I know! 

 

Where precision counts, go with the name brand blades (Fein, but I've also used these Bosch blades) or where there is scrappy, semi-demolition wood work to be done, I've used these much lower cost Actomaster blades. No matter what you choose, buy blades in bulk to save a few dollars, protect them in your kit, and use them wisely to save on wear and tear.

Bimetal #157 Blade. You can use it on wood, but it is designed for metal cutting.

 

Separate The Rail Elements

The lower portion of a porch railing is where much of the decay can be found.

 

Once the railings are down, it's time to take them apart. Parts that are really rotten will be easy to separate. Detach spindles from the bottom rail -typically attached with 16-18 gauge brad nails applied with a pneumatic nail gun. These nails are soft and flexible, and sometimes the spindles can be pulled apart from the rail. If they don't separate easily, you can use the Fein Tool to slice through these brads. The goal, for me, is to protect the milled pieces, so I am okay with leaning into the spindles with the cutter to spare the bottom rail. It is uncommon to find screws connecting the lower rail to the spindles because the heads would be visible.

The top board is typically a 2x4 and is usually connected to the spindles with phillips head screws. These should be easily removed with a cordless drill and #2 phillips bit. I would not expect the top board to need to be replaced as it is fairly well protected. Again, if screws do not come out, consider cutting them between the spindle and 2x4 piece with the bimetal blade. Anything in good shape can be saved and even improved. I'll show you, below.

Feintool Multimaster with sanding attachment can be used to sand railing components.

 

I go to my Feintool Multimaster and sanding pad attachment to quickly remove loose paint on any railing pieces I plan to re-use. The sanding pads, in all grits, come in boxes of 50. I use 60, 80, or 120 grit to remove paint on these pieces. These hook and loop pads are relatively long lived, but their most valuable feature is the ability to rotate the triangular pad to help with difficult corners. Before you jump into sanding square spindles (it is tedious), consider simply replacing them with new wood.

Basic spindles are cut lengths of 2x2 cedar, usually dry, smooth, and straight.

 

I want to replace all of the spindles, rotten or not. Why? Because the spindle is the lowest cost piece of the railing and too much effort to clean up the old ones. You can buy 8 foot lengths of 2x2 cedar at your local box store or lumber yard, but it may be even better to buy the 36 to 42 inch, pre-cut western red cedar spindles because these are straighter than the 8 footers. Another reason to buy new spindles is that this repair is really a modification requiring 1/4 inch more length than the original spindle so that they can be beveled ever so slightly. Lastly, the spindles are often beat up when they come off the porch and to mix new with old can look unkempt. For absolute cost savings, use the old spindles and expect to cut them shorter. Just make sure the nails and screws are removed before cutting!

A word about choice of wood: you may be tempted to buy treated lumber for any or all aspects of your repair project. I reject treated wood, typically pine, for porch railings. Why? It simply is not stable enough. Where I've used it, it has often twisted, pulled screws or nails, split, and formed mold on the surface where not painted. Painting it is also a problem, often requiring an adequate drying time before a coating can be applied. In that time, the drying process can twist or warp the wood. It's simply not good for this forward facing part of your home!

The simple, useful miter saw. Nothing fancy needed for this job.

 

You will need a miter saw for this repair. For spindle cutting, it does not need to be the costliest machine available. What I am using here is a 10" Dewalt DW703 I bought in 2004! Can't get that model anymore, so I recommend its successor, the 10" Dewalt DW713. If you don't have the resources for a powered saw, but have a mitering hand saw (good old barn tool find), it'll be much slower, but can be done! After all, western red cedar is fairly soft and easy to cut. Whether by hand or power, your blade should be reasonably sharp. The common 40t saw blade from Dewalt will work just fine.

First, cut your spindles 1/4 inch longer than needed. For example, if 6.25 inches is required length for the finished spindle, then cut each to 6.5inches. This leaves room for the coming bevel cuts. This bevel is important because it will spare you from rot returning as quickly as it had the first time by allowing water to shed.

 

Measuring accurately is important. -the blade tooth lands squarely on the 6.5 inch line.

 

Pro Tip: To ensure that all spindles are cut to exactly the same length (important!), clamp what is called a stop to the back fence of the miter saw. This can be done on a power or hand miter saw. I've used a piece of 3/4 inch thick plywood that I checked for square (see picture above) and ensured that it is mounted flat to the miter saw fence and table. Use a "C" clamp (pictured below) to ensure no movement of the stop.

Make sure that your stop is square and tightly clamped to the fence!

Pro Tip: Before making your cuts, be safe. Wear safety glasses and a dust mask, or what I prefer -a full face shield with lung protection. It offers better dust protection and full face projectile protection. Below is my 3M 6800 respirator. The 3M 6900 is readily available and great for a variety of pollutants. The particulate filters that come with the 6900 are good for this project and others. The silicone seal is remarkably comfortable given its level of protection and it is replaceable should it snap. Honestly, I wish I bought one of these 20 years ago. Protect yourself!

 

A combination dust mask and face shield  —the 3M 6800.

When your stop is in place, and are sure of the measurements, cut all the spindles needed for the project. After all the needed spindles are cut, it is time to make the final miter cuts.

After the bevel-cut: note the subtle angle between the spindle and square

 

Again, to ensure that all cuts are exactly the same length, we measure and clamp a stop to the back fence of the miter saw. Remember that these will be miter cuts, just a little bit off 90 degrees, so that the bottom rail points downward ever so slightly when installed. The measurement between the stop and the blade, set square at 90 degrees, is 6.25 inches.

Once that 6.25 inch is set, it is time to move the blade's miter position about 4 degrees away from the stop (moves blade to the left in this example) and lock it in place by tightening the front knob. Placing a 6.5 inch spindle between the stop and the blade, I hold it firmly with my right hand much closer to the stop than the blade. Triggering on the blade, I allow the motor to get up to speed, then cut through the cedar spindle slowly. I not do a quick chop down and jerk up! Hold the blade in the down position until it slows to a stop. This will protect the wood from tear outs and splinters while protecting you. Upon raising the saw blade, a slight angle will be visible on the cut spindle. 

Using a square it is easier to see the subtlety of a 1:12 bevel cut

This angle gives the spindle a length of 6.25 inches on one side and about 6.375 inches on the other. This little bit changes everything. A one eighth inch drop, across the spindle's 1.5 inch width, is the same slope as the 1:12 slope required to effectively shed water. It is the reason the bottom rail will now drain water instead of hold on to it. 

 

After all the spindles are bevel cut, ensure the bevel slopes outward when attaching to the bottom rail. Trust me —an 1/8th inch bevel can look like a square cut after a long day! So make sure that each has the longer side of the cut pointing outward on the bottom rail before attaching. See the image, below, to get a sense for the look. When mounted on the porch, the spindles will be plumb, but the bottom rail will tilt slightly downward, away from the porch.

 

On the bottom rail, it is hard to see the bevel cut, but it is visible in angle of the spindle

 

Pro Tip: There are times when it is easier to prime, and possibly paint, all the spindles before affixing them permanently with brads or finish screws. Priming and painting can be done after assembly, it is just a little fussier to do once assembled. This is entirely up to the you.

 

So is that it? It could be, or take rot resistance to the next level by reading Part II: Using Epoxy For Porch Railing Repair... where I will discuss using epoxy to restore components of the porch rail system, tips for attaching spindles and rails, filling holes, and the excesses to which I go to add longevity.

*Please note that the tools and products in this post are the one's I actually use, and if I link to a different product, it is only because it is a successor model to mine. 

 

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