How to Use Epoxy for Rot Repair Part 2: Advanced Applications
Hi, Todd Dermody here from Dunn Lumber. Today we're talking to Kyle Peterson, an independent manufacturer's rep for System Three products, whose products include laminating resins and epoxies such as SculpWood and RotFix. Kyle has many decades of experience as a rep with Daly's Wood Finishing Products of Seattle, and years' experience as a sales rep for numerous other painting-related products and finishes.
In this installment of our two-part series, Kyle answers our questions about System Three’s suite of repair products, and best practices for using them.
Q: What defines System Three products?
A: What makes System Three epoxies easier to work with is that they’re solvent-free. There are no noxious or volatile solvents in the makeup of these products, so they really have no significant odor that's bothersome. They’re also 100 percent solids, so in the use of these products, there’s no out-gassing of solvents or wastage. Everything is 100 percent efficient.
When you take the solvent out of the equation, it makes for an easier experience; if you smell noxious solvents, it almost induces panic—it makes you feel like you really have to hurry up. With System Three products, you don’t have that; you have panic-free work time.
Q: I find SculpWood, RotFix, Board Defense, and Bor-8 Rods on the shelf at Dunn Lumber—can you describe those products?
A: RotFix is our liquid epoxy, which is the penetrating consolidator and sealer for weak wood. When you apply this liquid epoxy, it’s going to penetrate into the wood, seal it, and become part of its cell structure. You’re essentially restoring the structural integrity of the wood.
When you have a space that used to have wood there, and you need to fill that area. That’s where the Sculpwood Putty comes in; it permanently replaces the wood you had to remove because of the dry-rot damage.
SculpWood Putty is the main volume of product you’re using for the actual repair—a one-to-one ratio where you take part A and part B, mix them together by hand (wearing gloves) to get a uniform color, and then pack it into the void or the area you’re wanting to repair. The next day—and it usually is the next day, when it’s fully cured—you can come back and tool it, scrape it, or sand it to make it flush with the surrounding wood again. This material is so wood-like it’ll hold screws and you can hammer it with nails. If you’re a woodworker, you can even use a router because it’ll hold shape just like the wood itself, and often even better than wood itself. It’s an amazing material, and part of the reason is that there’s literally wood flour in it as part of its composition, and that gives it an incredible wood-like feature.
Board Defense is a topical borate solution—a powder mixed with water—that penetrates and kills dry-rot fungus. Bor-8 Rods are hardened rods of this material. You strategically drill holes and embed these rods into the wood, and as water is exposed to these rods, the borate is wicked into the deeper areas of the wood to provide long-term protection against the dry-rot fungus ever coming back.
Q: Did I see SculpWood in a caulk tube? What’s that about?
A: Yes. We’ve been talking mostly about the putty—and I do think that's the primary product because bulk-wise that's the one that you'll typically be using most often—but we also make SculpWood paste, which is available in a caulking cartridge that mixes the two parts in the nozzle, so as you’re depressing your caulk gun, it’s fully mixed by the time it’s extruded. If you were up on a ladder and wanting to repair some fascia, you have it readily mixed by just squeezing the caulking gun. The main difference between the putty and the paste that is that the paste is creamier. It almost has the texture of joint compound, so instead of molding it by hand, you take equal amounts with a putty knife, quickly whip it together, and then use it for more confined areas. If you have cracks or small divots or voids, that’s actually the perfect thing to use because it's more pliable and spreadable than the putty.
Q: Do I have to use all three products together for it to work?
A: The essence of our System Three EndRot process is treating the wood with borates—the Board Defense topical solution or the use of the Bor-8 Rods. If you're thorough, it’s the perfect way to assure yourself that you're killing the source of the dry-rot damage.
If you can complete the repairs with RotFix and then our SculpWood Putty or SculpWood Paste, you're still going to have a repair that's going to essentially be permanent. The option of the borates is important, and it's a good one, but if you want to bypass that, you're still going to have a very effective repair.
Q: Two-part epoxies scare me, like they set super quick and before I’m ready. How long do I have to work with these products?
A: Liquid epoxies are a little quicker to fire off and start to harden faster than putties or paste. When you're combining the two-to-one ratio on the RotFix, it's always a good idea to spread it out in a fairly wide, shallow pan—if you mix it in a tight container, it creates more heat that fires off the product more rapidly. You can gain time if you pour it into a wider vessel. Once you do that, I have found that you've got a solid 10 minutes per mix to be able to apply the products.
When you’re mixing putties by hand, they’re not as hasty. You’ve got double the time to work with those—when you’re adding part A and part B of the putty and the paste, you’ve got a half hour or so.
One factor that does come into play with epoxies is that they’re temperature reactive. Your basic dry times are based on 70 degrees and 50 percent relative humidity, but if you have an 80- or 90-degree day and you’re working in that hot ambient temperature, these products will fire off and start to chemically react quicker. If you’re working with epoxies on a very hot day, you might consider mixing smaller amounts so you can easily work with those within that somewhat shorter time period. Mix as you go and work it piece by piece rather than mixing your whole batch and rushing to apply it all within 15 minutes.
Q: How long does it take these products to cure or dry?
A: The cure times for the putty and the paste are pretty much identical. There is a temperature factor, so in the winter I’d say you probably have to wait until the next day for the product to be hard enough to tool and sand, but on an 80-degree summer day, if you use these products in the morning, there’s a good chance it could be hard enough to sand and finish, by the afternoon.
Q: Will cured SculpWood accept stain? How about paint?
A: Yes. You can prime and paint it with both water-based and oil-based products. It will accept a stain, but because it’s a filler, it may have a different appearance than the wood surrounding it. If you’re priming and painting it, it will look identical to however you’re finishing the surrounding wood.
Q: Any last insider tips?
A: Because epoxies are so effective, they’re somewhat pricey; there’s no getting around that because they work so well. When you have repairs and it looks like there’s a fair amount of volume, people get sticker shock. One thing I’ve done with the putty is mix and pack it in, but then in the middle of the void—to take up volume and save money on the epoxy—stick clean rocks or golf balls in the middle of the putty. Just make sure your inserted objects are fully encased by the putty. Oh, and don’t put rocks or golf balls where you plan to nail or drill!
Check out part one of the series, where we break down the basics of epoxy.
