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Pore filling with epoxy - lessons learned
https://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=46380		 Page 1 of 3
Author:  Mike OMelia [ Fri Sep 18, 2015 9:36 pm ]
Post subject:  Pore filling with epoxy - lessons learned
I have as many of you struggled with pore filling, getting it right. I use z-poxy for dark woods, and have started using West System for other applications. I finally took ALL of Todd Stock's advice and used three coats of z-poxy. Etore squeegee. Those things are cheap and disposable. Buy the longer ones and cut to size. Toss when used. The rubber gets stiff with use. Even with a good DNA cleaning. To me, good for a project, then throw away. Use Caruth scraper, then a couple of wash coats. Then razor scrape, 600 grit soft sand, then scotch brite finish pads. I try very hard to not sand to wood. And seem to manage just that. I did not sand between the three coats. Yeah, it looked pretty "thick". But, wow. It worked. That's coco and waterfall bubinga. The bubinga was so porous!!! Not anymore.
Author:  Mike OMelia [ Fri Sep 18, 2015 9:38 pm ]
Post subject:  Re: Pore filling with epoxy - lessons learned
My point is, that's all epoxy. I haven't even sprayed the finish yet.
Author:  J De Rocher [ Fri Sep 18, 2015 11:54 pm ]
Post subject:  Re: Pore filling with epoxy - lessons learned
That's some killer bubinga. I just used zpoxy for the first time a couple weeks ago on Indian rosewood back and sides and a mahogany neck and I'm sold on it so far. The end result was dead flat surfaces and the zpoxy really brings out the grain. I didn't know that rosewood could have depth to it like the zpoxy brought out. The method I used was similar to yours. I did three coats and a final wash coat 1:1 with DNA, but I did sand with 400 between the first three coats. Like you, I didn't sand back to wood. I found that the zpoxy scrapes beautifully with a razor blade for removing any nibs or runs. I also found that those plastic AARP cards that come in the junk mail worked great as squeegees for the sides and back. I used a gloved finger to apply it to the the neck. If the stuff doesn't shrink back later, I'll be sticking with it from now on.
Author:  Mike OMelia [ Fri Sep 18, 2015 11:59 pm ]
Post subject:  Re: Pore filling with epoxy - lessons learned
I used to sand between coats, but found I was hitting wood and opening new pores. I suppose a lighter sanding would be OK to reduce final prep. But the idea as I've finally understood is to build into the pores. I've never had surfaces like this before. Scotch Brite was key for final prep. Try the Etore. It's way better than the credit card.

And no power tools!
Author:  Hesh [ Sat Sep 19, 2015 5:24 am ]
Post subject:  Re: Pore filling with epoxy - lessons learned
Nice job Mike! Very well done!

I very nearly quit being a guitar builder because of pore filling until I tried epoxy. Works great and some of my stuff is 10 years old now and no shrink back, no surprises.
Author:  SteveSmith [ Sat Sep 19, 2015 8:40 am ]
Post subject:  Re: Pore filling with epoxy - lessons learned
Mike O'Melia wrote:
... Etore squeegee. Those things are cheap and disposable. Buy the longer ones and cut to size. Toss when used. ...


Mike - that bubinga does look awesome! I've had good luck with Zpoxy (on bubinga too) but would like to find a better squeegee - Etorre makes a LOT of different models - can you provide a link?
Author:  rlrhett [ Sat Sep 19, 2015 11:42 am ]
Post subject:  Re: Pore filling with epoxy - lessons learned
You use the Caruth scraper on what? The whole body? Scraping the epoxy? Same question for the razor. When and how do you use that?


Sent from my iPhone using Tapatalk
Author:  kencierp [ Sat Sep 19, 2015 12:19 pm ]
Post subject:  Re: Pore filling with epoxy - lessons learned
I believe Japanese lacquer is traditionally leveled with a scraper. I have been using a single edge razor blade like a scraper as long as I have been applying finish to wood. Its an especially effective way of knocking down most defects -- sanding sometimes can be futile, even with a block one can make a mess (at least me). I do suggest grinding off the corners. Just try it -- I think you will like the results and find the learning curve short.
Author:  J De Rocher [ Sat Sep 19, 2015 12:31 pm ]
Post subject:  Re: Pore filling with epoxy - lessons learned
kencierp wrote:
Its an especially effective way of knocking down most defects -- sanding sometimes can be futile, even with a block one can make a mess


I agree with both points. When I apply the zpoxy, the edge of the squeegee or the AARP card leaves some thin ridges here and there. I bring those down level with the surroundings with a razor blade because it's much more effective than trying to sand them level. Same for any little bumps or thick spots.
Author:  Mike OMelia [ Sat Sep 19, 2015 1:07 pm ]
Post subject:  Re: Pore filling with epoxy - lessons learned
This is the squeegee. Etore blue handle. From lowes. I buy the small and big and cut the blade to about 5" wide. Whatever works best for the sides. Cheap. From lowes. I didn't believe it either when Todd said it was better. But it is.

http://www.lowes.com/pd_278374-1316-170 ... &Ntt=etore
Author:  Joe Beaver [ Sat Sep 19, 2015 1:08 pm ]
Post subject:  Re: Pore filling with epoxy - lessons learned
Good job pore filling Mike !!!

One question, what was the masking tape on the sides used for?
Author:  Mike OMelia [ Sat Sep 19, 2015 1:31 pm ]
Post subject:  Re: Pore filling with epoxy - lessons learned
Wow, thanks everyone! Been busy all morning. First thing, no power tools. Too easy to sand through.

Three coats. I did not sand between.

I use both the Caruth scraper and a card scraper (whole body and neck). I also use 220-320 paper on a sponge block during first sandings. Then move to 400. It takes about an hour to work the sides and back if that helps. I try real hard not to sand through. If I do, I avoid that spot. Before I apply 4th coat, I rub the surface (hard) with a soft, clean cloth, try to raise oils on any exposed wood. This is a very clean, flat, no drips or ridges application, not thinned. It should go on clean because surface is very smooth. Do backs first, let cure, do sides. Gently scrape and soft sand (600). Rub. Wash coat with a cloth. Light razor scrape, soft sand with 600, finish with scotch brite.

The other day I misplaced my Caruth scraper. And went nuts looking for it. I cannot imagine doing this without it. And won't even try that again. (Found it). I agree it sounds like a lot of work. Maybe it was.

Top was taped and covered in that plastic coated freezer paper you can buy at Walmart. Very nice product! After sides and back are done, I tape off sides to minimize risk of drips from top prep. One coat of West System 105/207, applied to top with squeegee, then rubbed off with a clean blue towel. Added more to rosette (to fill), that gets scraped off later.
Author:  Mike OMelia [ Sat Sep 19, 2015 1:36 pm ]
Post subject:  Re: Pore filling with epoxy - lessons learned
I'll post a pic of the finished bubinga rosette later
Author:  SteveSmith [ Sat Sep 19, 2015 2:09 pm ]
Post subject:  Re: Pore filling with epoxy - lessons learned
Mike O'Melia wrote:
This is the squeegee. Etore blue handle. From lowes. I buy the small and big and cut the blade to about 5" wide. Whatever works best for the sides. Cheap. From lowes. I didn't believe it either when Todd said it was better. But it is.

http://www.lowes.com/pd_278374-1316-170 ... &Ntt=etore


Thanks Mike
Author:  Mike OMelia [ Sat Sep 19, 2015 10:48 pm ]
Post subject:  Re: Pore filling with epoxy - lessons learned
Btw, that water fall bubinga... Got that from Shane at HMTW. Shane, hope u like how I'm treating it. Very pretty wood.
Author:  Tim Mullin [ Sun Sep 20, 2015 8:23 am ]
Post subject:  Re: Pore filling with epoxy - lessons learned
A question: why are you trying to leave a layer of epoxy on the surface of the wood? Why so fearful of sanding to wood? Just because you'll open "new pores"?


Sent from my iPad using Tapatalk
Author:  klooker [ Sun Sep 20, 2015 8:50 am ]
Post subject:  Re: Pore filling with epoxy - lessons learned
Tim Mullin wrote:
A question: why are you trying to leave a layer of epoxy on the surface of the wood? Why so fearful of sanding to wood? Just because you'll open "new pores"?


In my experience with Z-Poxy, if you don't get a uniform surface, either only the pores filled or pores & thin layer over everything, you will get shadows, DAMHIKT [headinwall]
Author:  Nils [ Sun Sep 20, 2015 12:31 pm ]
Post subject:  Re: Pore filling with epoxy - lessons learned
I also pore fill with z-poxy. Typically I sand back to wood, but try to keep the epoxy in the pores. It typically works well. Additionally, I don't go higher than 220 grit. I finish with nitro. If I see small pores in like 6 months, it doesnt really bother me.

I'm not saying that 600 grit with no exposed wood is problematic, but if there is exposed wood, when your finish hits it, I like to think it will raise the grain a tad making a stronger link. I also believe that 600 is also not ideal for adhesion in this situation because you need something to bite into.
Author:  kencierp [ Sun Sep 20, 2015 5:16 pm ]
Post subject:  Re: Pore filling with epoxy - lessons learned
Purposely leaving a thin layer of Zpoxy has not been problematic for me and it is certainly is less work versus sanding off all but what's in the pores.
Author:  klooker [ Sun Sep 20, 2015 6:49 pm ]
Post subject:  Re: Pore filling with epoxy - lessons learned
I believe the Scotch Brite after the 600 is to give it some tooth.
Author:  Mike OMelia [ Sun Sep 20, 2015 11:43 pm ]
Post subject:  Re: Pore filling with epoxy - lessons learned
I was wondering when the critics would show up. Frankly, I have no idea if this will succeed. I hope so. My plan is to scuff and wipe with DNA before first coat. My first goal was to avoid uneven finish (shadows) while keeping pores closed. This surface is very thin. The 600 was not for achieving glass finish, but to avoid sand through. Scotch brite was for surface finish. I agree there needs to be some texture for bonding. But I have no idea what that needs to be. Molecules are small thins, way smaller than 600 grit. Least, that's my operating theory.
Author:  J De Rocher [ Mon Sep 21, 2015 12:05 am ]
Post subject:  Re: Pore filling with epoxy - lessons learned
Mike - Have you seen Hesh's toot on zpoxy? http://luthiersforum.com/forum/viewtopic.php?f=10117&t=20320

Here's a quote regarding sanding to wood or not in case that is your concern about whether or not "this will succeed".

"There are two schools of thought when using epoxy as a pore filler. Some folks like to leave a thin epoxy film on the entire surface of the wood for it's beauty and wetting properties. Other folks like to sand the epoxy back to the wood leaving it only in the pores.

Both methods work well."
Author:  Mike OMelia [ Mon Sep 21, 2015 7:30 am ]
Post subject:  Re: Pore filling with epoxy - lessons learned
I tried thinking of a better word than "critic". Nothin occurred to me. Hope no one thought that was me being snarky. I was serious. I was wondering when someone would mention it. And it also occurred to me that Hesh didn't say anything about it. We all used to have long discussions about proper use. And, like was said above, there were 2 schools. Sand back to wood, or leave a thin layer. Both have challenges. Thin layer school means you can't have any sand through at all, lots of hand work. Wood school risks pore opening. I think it's almost impossible to avoid depending on wood species. Over scuffing thin layer leaves lines you can't buff out, but DNA somewhat "activates" z-poxy".

So, we'll see.
Author:  Shane Neifer [ Mon Sep 21, 2015 8:18 am ]
Post subject:  Re: Pore filling with epoxy - lessons learned
Mike O'Melia wrote:
Btw, that water fall bubinga... Got that from Shane at HMTW. Shane, hope u like how I'm treating it. Very pretty wood.


I do indeed Mike! I have quite a few sets left and I am not at all sad about that as I plan to start making a few guitars this winter. I don't have many with that nice sap wood though. Looks completely awesome Mike! I also have the longer EIR Harp sides now so once I get things set up in the new shop this winter I will be in touch.

Thanks
Shane
Author:  Fred Tellier [ Mon Sep 21, 2015 9:08 am ]
Post subject:  Re: Pore filling with epoxy - lessons learned
I used Z-poxy on a few guitars, both sanded back and thin layer and after a few years I detected sink back into the pores, I now use the West system epoxy and do not see the sink back with it. I loved the fast cure time of the Z-poxy but the other than the slow cure time the West is a much better product. The clear color of the west shows less color change so sand through areas are quite easy to hide.

I scuff the 1st coat and apply the 2nd before I do any sanding to avoid sand through. I have never used the filler so on deep pored woods I use an extra coat if needed.

Fred
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