Drywall formula pore filler

[Herman]

Ready for finishing procedure. First Fill all the minor gaps with matching wooddust en CA-glue.
Then time for sanding. The most uneven joint were scraped flush before and now I sand with a sandingblock and 150# paper. The walnut is quite soft so the sanding is easy. (Had hard maple earlier that was a hell to sand)

The surface was whiped with shellac sealer because I want to avoid that the stained filler colors the delicate wood and the maple bindings. The filler I use is made accordingly to Robbie O'Briens video. Means: Fine grained plasterfiller with brown and a drop of black. Costs: about 2 cts! (These days I only use the Stewmac liquid dyes for everything.)
Standard method: thick paste whiped in circles into the pores. Leave it a day for drying/shinckage.



Maybe object for discussion:
The last 2 guitars the filling was Z-Poxy. Works great as a filler, as long you dont sand back into the wood.(Leaves visable marks)
These guitars turned out good, but in the back of my mind I feel reluctant to the use of rubberish material on a guitar. Z-Poxy becomes hard, but not "brittle-hard". Does it affect the sound? Probably none of use will make 2 identical guitars with and without epoxy.
I know some of us, amongst Ken, like the epoxy. But well, I keep having doubts.

[ken cierp]

I think Timbermate is similar to the drywall compound -- and is not a exactly a paste fill either. I've used Pore o Pac water based paste filler and did not care for it at all. In my view you are using much too thick of medium to get it down into the pores which could be a problem later - capping instead of filling the tiny holes. Filler needs to have some "flow out" just like any other coating. Martin "paints it on with a brush and burnishes into the pores with a wheel. Zpoxy is anything but "rubbery" and that is one of the things that makes it (in my view) such a great product for use in our craft. A rubbery material does not sand off as easily as Zpoxy. Sand through can be easily corrected by re-coating with the Zpoxy thinned with alcohol. Since filler is not used on the sound-board the impact on the sound quality -- well there is none.

[Tim Benware]

I've used Timbermate, wasn't thrilled with it. I keep going back to System 3 SB-112. I now apply two coats, the first one is just the resin and hardener and is thin so it flows well into the pores, the second coat I add silica to thicken it and it fills the remainder of the pores depth very nicely.

[Herman]

I used several different fillerproducts, but none of them I find 100% satisfying. The Z-poxy fills very well and stays perfect under the laquer I use. It fills the best of the products used. So for that, no arguement from me.

But about the hardness over the remaining epoxy I disagree. To me it is not hard enough. But maybe everyone must sense this for its own. There are more roads to Rome, we say.

The plaster filler I used before and that worked fine, no problem with the finish after 3 years. Only on that guitar I did not seal the wood, therefore it colored a bit brown. We see how this works out this time, after sealing.

[Kevin in California]

I really like the Timbermate and haven't tried the drywall compound yet, but I do suppose it is similar. When I used the ebony colored Timbermate on EIR I thought it was fabulous. When I mixed some ebony and rosewood colored together and tried that on EIR I was not as pleased as the color in the pores showed more. So color of the filler is very important. With clear, no worries. I've tried clear and I like that look too. I want to try the new aquacote clear waterbased filler that LMI is selling.

[ken cierp]

Not to belabor the point -- but most complete guitar lacquer "systems" including Mohawk, Behlens, Seagrave etc. all use several coats "vinyl sealer" in the process which by design is flexible. And the claims of the top coat material being formulated to be "flexible" and resilient is part of the marketing as well. Now this formulation is to help prevent checking long term, so it would seem that a coating that is too hard might not be a good idea? Just a conversation starter -- my view is that, in the guitar making arena there are no absolutes or bests.

[Kevin in California]

yep a coat of the vinyl sealer goes down before any pore filling