Wood Hardeners

[unclej]

i've got a great looking piece of spalted maple for my next project. it's got a little more punky area than i'm comfortable with so i've been researching wood hardeners. they all seem to be solvent based epoxies but the one bit of information that none of the sites i visited offerered is how clear they dry. i don't mind a bit of ambering but i sure don't want milky.

any recommendations and experiences? brands to look at? minwax offers one that would probably be easy for me to get. anyone tried it?

thanks

unclej

[n8rofwyo]

I have used the Minwax hardener. I didn't get any cloudiness, but I grain filled after using the hardener and the grain fill seems to stand out a little more than I like. Grain fill was rottenstone and 2 lb. cut shellac. Don't know if that helps but its all I have on the subject.

Nate Robinson

[unclej]

thanks nate..that does help. don't know if i'll even need a grain filler so i'm not too worried about that..thanks.

[mdw3332]

I think that Drak is the one that recommended using CA.

[Drak]

If it's really really punky and soft (advanced rot spalt) I would highly recommend the CA, it works GREAT for my advanced spalt.

On top of the fact that it dries crystal clear, it also seeps into the spalt and hardens it up real nice. The 2-part epoxy, even thinned down, would never get near the 'soakability' of the red CA, it soaks in like water to a sponge. I use those black sponge-brushes to apply it. Work it in in small sections at a time and let it soak in all it wants to.

CA also dries rock hard and gives a great flat surface to start your finish on also.

But you HAVE to have a respirator AND goggles AND do it outside, it is incredibly toxic for about 3-5 minutes, and really until it's dry, but the worst is the first 3-5.

Otherwise, it's 2-part epoxy, the Devcon or whatever brand your Home Depot is selling. You will want to thin it down with Acetone tho, which also extends the drying time window.

You have to remember, you're just filling grain and pores, you're not building a finish with it.

Every spalt guitar I've done looks fantastic and came out great following these recommendations.

Keep it (the wood) thin too if the spalt is advanced. Advanced spalt is like balsa wood, and is not only tone-deficit, but is actually a tone-sucker, it is like negative tone, black hole tone, so keep it thin unless it's just average hard spalt.

I've had spalt as hard as any eastern maple you'll ever see, and spalt that was soft as a sponge, there's a great variation between pieces.

Good luck and post some pics, I love spalt!

[unclej]

thanks for the advice drak..the punky area is only about the size of say a couple of silver dollars end to end. then there's a few small places that are more porous than punky. sounds like the ca is the way to go. and pics will definitely be posted. the walnut cap has some great figure in it and i think it'll look great with the spalted maple.

just a little aside..one of my favorite guitars that i made was from a solid piece of spalted pecan that was cut at just exactly the right time. plenty of spalting but no softness in it at all. great look and sound.

hate to sound like a total nimrod but you mentioned red CA and i don't have any idea what that is. can you enlighten me a bit?

thanks

[Drak]

Yes. CA glue usually comes in 3 consistencies:

Red - thin, runs like water

Yellow - medium consistency (for overall use, I use yellow far more than the other two)

Green - thick like syrup, gap filling consistency, but really slow to dry. I hardly ever use this one, almost never really.

PS, do not be tempted to use the accellerator while doing this, let it dry on it's own.

[Guitarfrenzy]

....

PS, do not be tempted to use the accellerator while doing this, let it dry on it's own. 

←

Very true Drak, the accelerator will make the CA and wood turn yellow.. lol At least that's from my experience with it also.

[Drak]

I added that because CA accepts moisture when it dries, and when you use the accellerator, the glue can dry too rapidly to an opaque white instead of crystal clear if left to it's own devices.

[unclej]

thanks again gentlemen..i think i'm all set now.

[guitar2005]

I'm tempted to use the Minwax wood hardener because it is easily available and comes in large enough quantity to do a guitar top.

I'm intrigued with the CA glue option though. I wanted to try this but wasn't sure if it was a good idea. I'd have to buy several bottles of the stuff and some people on this board have said that it can create some blotchyness on the wood.

This is for a 1/2" Black Limba top (see pic below). I'd really like to hear the pros and cons of both methods. drak mentioned adding some acetone to the minwax hardner. Would that would as well as CA? If I were to use CA, how much would I need?

Edited January 7, 2007 by guitar2005

[Mattia]

Sorry, but is that limba actually soft? Punky? Looks like standard colouration to me, with the worm holes pretty much all black limba has. Fill with epoxy, and move on.

[guitar2005]

Sorry, but is that limba actually soft? Punky? Looks like standard colouration to me, with the worm holes pretty much all black limba has. Fill with epoxy, and move on.

Yes, I'll fill the worm holes but I want to actually harden the wood as it is very soft. Almost like pine.

[unclej]

i see that this thread has been resurected so i'll add that i used the minwax hardener on the above project and have used it a couple of times since on some art projects and was very satisfied with it. easy to use, great shelf life and dried very clear. the only suggestion that i'll make is get plenty of sand paper. the minwax loads up fairly quickly at first an if you over use the same piece, especially on a random orbital, the minwax that has loaded up will harden on the paper and actually create fairly deep swirls in the wood that are tough to get out.

good luck.