Aqua Coat Clear Grain Filler

[Paul Rhoney]

Have any of you guys tried this stuff out yet? I have one good report on it, saying that is fills well, and doesn't shrink back.

http://aquacoat.com/collections/product ... ain-filler

[David King]

Never seen it but I've heard really good things about this stuff:
http://www.woodcraft.com/Product/148740 ... tural.aspx
from folks who build a lot more instruments than I do.

How can it be no shrink? That seems impossible for a WB product.

[Paul Rhoney]

David, have you really never tried TimberMate? I'm surprised! It's so common these days. I've used it many times, it's ok, but what works better is Gork's GoodFilla. It's actually made by the guy that invented TimberMate, but it's his next step of evolution on the product. The particle size is smaller, it's non-abrasive, has better adhsesion, and doesn't smell so terrible. It's all I'm using for grain filler currently, and it's the best I've ever used.

However, I don't particularly care for the way any opaque grain filler looks. All the best finishes I've ever achieved were done by just spraying sealer or clear coats over it, sanding it back, spray, sand, spray, sand, until every single little pinhole was gone. Wood just looks so much better that way in my opinion.

[David King]

Paul,
No arguments there. The last paste filler I used was that oil based stuff made by Kyanize about 25 years ago.
I have been using West epoxy or medium CA ever since.

[Paul Rhoney]

I thought it might be worth reporting on my first use of this stuff.

I had a guitar with an African Mahogany body that I had already started finishing before I'd heard about Aqua Coat Clear Grain Filler (ACCGF). Because at the time I thought I'd be strictly using an opaque grain filler, my regular Gork's GoodFilla water-based filler, I sprayed it with a very thin coat of Urethane Tie-Coat, and then covered it in the GoodFilla. I then sanded it back and sprayed a single thin coat of Urethane Sealer over it. It was still very much open-grained, almost as thought the GoodFilla hadn't been applied, although you could clearly see it in the grain.

This was the point at which I received my quart of the ACCGF. After lightly leveling the Urethane Sealer coat with 400 grit, I slathered on the ACCGF with my fingers. It's very easy to spread, and the can clearly says that you only need wash skin with soap and water when coming into contact with it. As it goes on it has a sort of milky haze to it, and does not appear to be crystal clear. If you've ever used the Target water-based lacquer that Stew-Mac used to sell under their ColorTone branding, well it looks like that. With that stuff, if you put too much on at a time and didn't let it fully dry, it would stay milky hazy looking. With the ACCGF however, after giving it ample drying time (I'm estimating about 2 hours) it does become totally transparent. So back to what I did with it, the first slathering of it was now dry, and I just did the same thing, slathered on another "coat" with my fingers. I tried not to use too much pressure, I wasn't meaning to push it into the grain, so much as just kind of lightly wipe it on, letting the surface tension keep my fingers a microscopic distance from the surface, and allowing the evaporation of the water in the product to slink it down into the grain. At this point I had to leave for the day and come back to it.

When I picked it up again, I decided to see where things were at and I sanded it, again with 400 grit. I only touched the front, back, and sides, keeping away from the edge roundover (think Tele-style instrument). It was obvious at that point that there was grain that was much better filled than it had been before. Keep in mind that I had previously started a grain fill on it with the GoodFilla, so there was already some filling of the grain, but it did still appear very open grained before I ever applied any of the ACCGF. I slathered on a third helping and let it dry overnight.

This time when I came back to it, I thought I had messed something up. Like maybe I did little more than pull the previous coats of grain filler out of the grain when I did the third coat, I thought most likely because I sanded it when maybe I shouldn't have. Holding at an angle to the light, I thought I could see open grain everywhere like I hadn't put anything on it at all. At this point the surface was beginning to seem uneven because of the streaks from so many coats of the ACCGF, so I decided to sand it again. Here's where things got surprising: sanding was easy and the grain appeared to be almost completely filled. I guess it only looked like the filler had done nothing because there was a layer of it on the surface around the grain. Once that layer was gone, it was obvious that the grain was filled.

Now one issue I had at this point was that I burned through all layers of finish down to the raw wood in multiple little areas. On this particular guitar a mostly opaque finish was sought, and if it really looked bad under the color, I could put a solid color finish on it, and nobody was gonna be upset. It's just a stock guitar I'm making for NAMM, not a customer's guitar with specific finish requirements. So really this wasn't a problem, but I was interested in one particular fact. Those of you that have used TimberMate, and GoodFilla, and in my experience some of the oil-based fillers, such as Bartley's or Cardinal, know that if you put that stuff over a coat of some kind of sealer, and then you burn through, the filler immediately comes right up out of the grain. There's also always the problem of when you sand a grain filler and you blow off the dust with your air nozzle, while some of the filler may stay put, you might also blow some of it right out of the grain there as well. However, the interesting thing so far as that ACCGF does not have that problem. This stuff stays put. Whether I burned through or not, if the grain was filled, it stayed filled. There were spots that I missed, and spots where I probably just didn't get enough on there in the first place. So my test guitar isn't quite flat and level yet. But I sprayed a fairly heavy two coats of sealer on it, and I think my next level sanding of it will be my last.

That's probably more than any of you felt like reading about any product, but I'm optimistic and excited about this stuff, and I have yet more to say. You see as I mentioned in my previous comments I don't like the look of opaque grain fillers, but when using them I've always found that applying them after a thin coat of sealer gives it the most natural look. The difficulty there is always that you can burn through that thin layer, which also doesn't look good, and often one application of the opaque grain filler is all you can get away with before it starts to look really unnatural. My test guitar had some of those issues to deal with, but I think I have a pretty good idea of how to approach things on the next one. The big thing is that if my grain filler is gonna be clear, I don't need to worry about applying it over just a thin coat of sealer. Basically I can hog on as heavy of a coat of sealer as I want to, and then apply the grain filler. I believe that I'll be able to apply the ACCGF over the sealer without sanding it (adhesion doesn't appear to be an issue), then after the coats of filler go on (I'm still estimating that three coats will be needed), then I'll finally sand it and if I do it right, it should be mostly level, and I can thin out that heavy sealer coat with the sanding. Perhaps one more regular thin coat of sealer, and then I'll be ready for sealer.

Yes, that's still a lot of steps, and it's not terribly short on time. If the ACCGF and/or sealer were faster-drying products perhaps I could go from raw wood to color-ready in a day. But I'm guessing it's going to be at least a two-day process. What's nice about it though, is how little sanding is going to be required. In theory I'll only have to do that one level sanding.

[David Falkner]

How does it compare to ZPoxy?

[Paul Rhoney]

You know I don't have much experience with Z-Poxy, but I think for me anyway, this stuff is easier to use.

I've changed the way I was applying it recently and I feel like I'm getting much better results. I use a piece of a cut up old t-shirt to rub it into the grain, and really try to wipe as much of it off of the surrounding surface as I can. I'll move on to another area even if it doesn't look completely filled, because I know the stuff needs to dry and it will shrink a little in that process. So later when I revisit the same area, I apply more and it'll fill little by little each time. Most importantly I feel like this stuff will get into the deep grain that my sealer doesn't want to flow into. If I can get a pore half-filled with the Aqua Coat (I'm still using Gork's GoodFilla for solid color finishes), that's usually enough to block it off and allow the finish to do the rest.