Official Luthiers Forum!

To those of you who use West System epoxy to fill the pores on your guitars, I was wondering what number of the hardener you use in conjunction with the 105 resin. There are at least four different hardeners so I'm confused on which one to use. Thanks for your help!

Steve H.

I'm using 206 because that's what was on the shelf the day I went to buy mine.

I told them what I was going to use it for and they said that there was a hardener that would make it water clear, but that this was pretty close to clear. It would also have to be ordered in and take a week. I didn't want to wait so went with what was available. I haven't been able to detect any color shift with this combo. It looks almost as clear as water.

I don't know if any of there hardeners affect dry time. This one has a really long open time so there's no rush trying to get everything filled before the product starts to go off. I let it sit 24 hours before sanding it back.

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Allen R. McFarlen
Barron River Guitars & Ukuleles
Facebook
Cairns, Australia

I've used the 205 hardener for almost 20 years, and never had any
problems. I typically use epoxy only as an adhesive though, and not a filler
or finish. When I was working on boats we would use the 207 for finish
coats, either brushed straight on or thinned with acetone for spraying. It
may be slightly higher clarity, though the 205 is just fine when it's fresh. The
main advantage of the 207 for finish work is increased UV resistance.

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Eschew obfuscation, espouse elucidation.

Steve-
205 usually for me, for pore filling and adhesive use- unless it's really hot in your shop you're not likely to need the longer working time that 206 will give you.
207 works fine as well for finishing- the mixing ratio is different, but the WEST pumps take care of that for you. I wouldn't bother buying 207 unless you want to have it around for other (eg boat) projects.

Cheers
John

I like the 206 just because I don't have the honed skills most here do.  It allows me a little more time and it is a tad thinner than the 205 which is a benefit in a few instances.  I'm sure either will be fine.  Is Rick still gone? I believe he said he likes the 205 because it works faster, but the other guys in the shop like the 206 for the longer working time.  So the 206 has a longer working time and is slightly thinner than the 205.  Now it just depends if those seem like necessary benefits to you, if not 205 will be fine. I like the extra time just in case, but honestly before using west systems I was using some 5 minute stuff without any problems, so the amount of time the 206 gives you is not necessary, but I don't see it as a negative really, just personal preference. Best of luck, I was very happy with that purchase.  Just don't forget the little pump set!!!!!  Jason

I'm back.   Yes, we use 205 and 206.   I'm loving the stuff more and more.   I find now that I can do my sunburst stains right over the epoxy, then seal them in with Waterlox and move on to McFadden's rosewood sealer and polyester just fine.   

I wouldn't use hardware store 5 minute stuff. It swells and contracts weirdly over time, and the West stuff is dead stable.

Rick, you are doing the bursts and stains over the epoxy on backs only right? Not tops?  Welcome back!

This brings me to another question. Is it okay to use the west system
epoxy to seal the top of a guitar? I always have to do sveral sessions of
spraying the lacquer then sand back in order to get all the minute pores
in the spruce filled>
Steve H.

[QUOTE=Steve H] This brings me to another question. Is it okay to use the west system
epoxy to seal the top of a guitar? [/QUOTE]

Steve-
You will get different opinions on this.
I'm in the 'no epoxy on the top' school of thought.
WEST (Gougeon) claim that the epoxy penetrates and saturates the wood some distance (WEST=wood epoxy saturation technique), and I'd rather avoid that in a soundboard. (This requires one to ignore the saturation of lacquer, shellac, etc into the top, but there's no rule that you have to be logically consistent around here!).
I've never had visible pores in a spruce or cedar top- I sand with sharp paper and a hard block to 220 grit and then start laying on the finish I've chosen.
Some classical guitar builders seal/size the soundboard with egg white before french polishing- I think that egg white was the only finish on some old lutes, but you'll have to check with the experts on that.

Cheers

John

I'm not using epoxy on spruce or cedar tops, but I am now shooting my MEK dye stain bursts over it, and it seems to work just fine.   I'm still "setting" the stain with Waterlox OVER the epoxy and then sealing that with McFadden's rosewood sealer. So far, so good, and the look is what I'm after.

[QUOTE=Rick Turner]
I wouldn't use hardware store 5 minute stuff. It swells and contracts weirdly over time, and the West stuff is dead stable.[/QUOTE]

Agreed on avoiding the hardware store 5 minute stuff.  This is a picture of the first day I tried west systems http://i21.photobucket.com/albums/b256/jmrentis/Guitar%20Bui lding%20Pics/IM000627.jpg  I was so impressed that I was forced to show my happiness with a picture.

The difference between the two was almost unbelievable to me and those are just differences in application not even in final product.  Since switching I've found so many more uses for epoxy, its great stuff. Jason