I am finally making a real work bench, and have used hard maple from a local sawyer for the top. It’s pretty clean, but there are a couple oblique knots that I couldn’t avoid, so I am thinking of saturating them with marine epoxy to stabilize them. Then I thought: why not spread a thin coat of epoxy on the entire top, then finish sand? I have used epoxy for kayak building, and it will seal and strengthen the wood (not that maple is weak). I had the top flattened on a wide-belt sander at a local shop to 80 grit (too much for me to plane, even with the #8), and plan to sand to 150 grit with the random orbit. Does anyone have experience using epoxy in this way? I would hate to ruin the beauty of the sugar maple with a bum finish. Will the epoxy be a real crackly mess when the bench gets the inevitable divit from a misguided mallet or chisel?
Dane Liston
Replies
hi,
i just wanted to remind you that epoxy is more effective sealant than most other finishes (it's marine grade),therefore it is important that you apply epoxy on both sides of your benchtop in ordre to keep it coppletely stable under changes of humidity. in all other aspects i think that if you like the appearance textore and durability of a test piece it is fine.
regards,
ami kronenberg,israel [email protected]
Dane,
I took some classes in my school's furniture design dept when I was in grad school... the community benches in their shop were maple and I was told were covered in epoxy... they seemed to have held up fine after much abuse.
The crackling your thinking of( I built a cedar-strip boat too, so I know where you're coming from) ...I believe comes from the outer shell of epoxy delaminating from the fiberglass cloth and wood... since a kayak/canoe's hull allows it the cured epoxy to flex during a blow. I don't think the solid maple bench would do much flexin' so you should be good.
I used to make work and lab benches, most had no finish. Sometimes epoxy was specified for a finish. I subbed the finishing out to a boat shop as I did a lousy job on my first and last try.That bench turned out nice after a lot of scraping and sanding.
If you have experience with epoxy,go for it.My biggest problem was with drips that made an uneven surface. I spent 6 hours sanding and scraping. $100.00 for each bench finished at the boat shop was worth every penny to me.
mike
I wouldn't do it.
Bench tops get wear and tear and the occasional scratch, ding, or gouge and glue drip unless you are an extremely careful worker. A top can also develop a warp or twist, especially during its first year of use, and that will need to be planed out. The traditional oil finish used on bench tops takes all of this in stride and can easily be scraped and renewed when needed.
You also don't want a top to be slick and slippery which will cause stock to slide away during operations like laying out and sanding, which are easier and much faster to accomplish if you don't have to clamp down the workpiece.
John White, Yestermorrow School
I don't mean to but in, but I am about to finish my bench top made from glued 2x4s. I planned on using clear lacquer. Would the epoxy be better since pine is softer then maple?
If they are commercial 2 by 4's they probably aren't white pine, they are much more likely to be spruce, hemlock, yellow pine, or Douglas fir.
In any case, an epoxy finish isn't a good choice over a softer wood. A hard finish doesn't make the wood itself harder and dents and dings will cause the finish, which isn't flexible, to just flake off over the damaged area. You are probably going to have the same flaking problem with the lacquer along with the all the other drawbacks I already wrote about for the epoxy. A bench top is a heavily used surface, save the lacquer for pianos.
John White
I agree with John. At some point your work top will need to be repaired, and I don't think epoxy is an eminently reparable finish. I have a maple butcher block bench top that I am currently refurbishing with a cabinet scraper. I don't think I'd be able to do it if it had been epoxied. An oil finish or even shellac would be easier to repair than epoxy or varnish.Glaucon
If you don't think too good, then don't think too much...
I feel the need to point out one of the primary virtues of epoxy, it is WATERPROOF. A benchtop sealed all four sides with epoxy will not warp or twist, as the moisture content cannot change.
I built an extension table for my unisaw and finished it as such, yes it is as slick as you say, but that is ideal for this application. If you want it a bit rougher just hit it with some 100, 120 grit sandpaper.
One suggestion, take the time to smooth it before it dries! You don't want to have to scrape it smooth once it hardens!
When I built my bench I chose to buy a pre-made top that had a hard glossy finish. It looked great. However after chasing the workpiece all over the top (even clamps were difficult to hold it), I got the beltsander out and took the finish off then used an oil finish. John and other's suggestions of being able to renew the top and finish make good sense. IMHO
Just a random thought, having played a great deal with a variety of epoxies. I dont read anything above that I patently disagree with, and think Johns rationale of a benchtop and why not to epoxy it is valid. Nevertheless, I tend to be the kind of guy that says I want to do it this way, and regardless of input, there ya go.
So the thought is, to keep it from developing any huge film, but to give you the benefit you are seeking which is pretty much, as I read it, inpenetrable sealer, you can change the viscosity of epoxy in two ways. Depending on the density of the surface you apply it to, you could conceivably get it to absorb some into the wood, though with maple, I dont know how much.
For whatever the thought is worth, #1 is an epoxy reducer and fair warning, it'll take your nose hairs off. The down side to reducers is they degrade the strength of epoxy coatings but in your situation I doubt significantly, and the reducer flashes off far faster than the epoxy can begin to cure with what you're doing. I use reducer primarily when I have to get epoxy deep into something like a large porch column and simply can not get the heat gun (#2) to do anything useful in there.
#2 which would be my attempt if I were to try it, on scrap first, is a heat gun. The upshot of a heat gun is you change the viscosity like, right now! It'll go from molasses to alcohol in seconds, the down side is epoxy cures via heat and you can not sit there and heat it and heat it endlessly or it will simply harden AND likely bubble on you. If you get to the point where it begins to foam, you've gone too far. What I'd be looking for is to see if the heat would make it soak into the wood, and almost immediately, and if so, I'd leave it alone after that and let the reaction take its course, and I would try to remove any excess from the surface before I let it sit and cure.
While I've had great luck with that in repairing things, the accolade is things that need repairing usually have gotten soft, porous, or punky. Like I said your pristine sugar maple may not accept it so readily.
Real trucks dont have sparkplugs
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