another finishing question

[jonnyschanny]

Hi everyone. Sorry to bother you again. I've been trying to do more research on finishing and came up with some questions.

From what I've gathered, most people will fill open poor wood, since it gives it a smoother surface. However, I've also read of people sealing the wood before filling it, then sealing it again before putting on the finish. And then you can have stain applied as well, which some people say you should do before filling and some say do after.

My question is: Do you need to seal the wood? I don't plan on staining. I just want to fill the pores, then put the finish on that, probably tru-oil.
Can I just use the filler, let it dry, sand it down to smooth, then apply the tru-oil finish? Also, do you guys put down a layer finish on the top first to keep the filler from staining it on accident before you go on to the other parts of the guitar?


Also, anyone have advice on what fillers work well with tru-oil? My guitar is East indian rosewood that has a slight purple tint to it. z-poxy? The aqua coat filler from LMII?

Thanks for your advice!

Jonathan

[Hot Vibrato]

It's not necessary to seal the wood before doing grain filler. The darker paste filers will stain your wood though if you don't seal it first, but you might actually like it better that way. A mahogany neck that has been sealed first will be much lighter than one that was not. It will look great either way. It's just a matter of preference.

I do think it is necessary to seal rosewood before using paste filler. Otherwise, the filler will stain your rosewood too dark.

At some point, you have to stop reading and start experimenting on scrap. Don't commit to any finishing decisions on your workpiece until you achieve acceptable (and repeatable) results with scrap wood.

[charles Tauber]

Originally Posted by Hot Vibrato

At some point, you have to stop reading and start experimenting on scrap. Don't commit to any finishing decisions on your workpiece until you achieve acceptable (and repeatable) results with scrap wood.

Good advice.

As HV alludes to, the specific methods will depend on the specific finishing materials you decide to use and your environment. For example, I use paste fillers that I tint to suit the wood color I'm using. I strongly advise sealing the surfaces prior to application of a paste filler, else you risk staining light-colored purfling and top woods. It may not be necessary if using uncolored epoxy-type fillers.

In short, it is what works for you, your skill, your experience, your available equipment and your environment (e.g. hot, dry, cool, wet...). You can start off by following someone else's "recipe" of what worked for them, but, eventually, you'll need to alter it to what works best for you and your situation. Always test on pieces other than your nearly completed guitar.

[Rodger Knox]

Originally Posted by charles Tauber

In short, it is what works for you, your skill, your experience, your available equipment and your environment (e.g. hot, dry, cool, wet...). You can start off by following someone else's "recipe" of what worked for them, but, eventually, you'll need to alter it to what works best for you and your situation. Always test on pieces other than your nearly completed guitar.

My typical finish is TruOil over a shellac seal/pore fill. I post my recipe if you're interested. It's not quick, but it is reasonably easy.

[jonnyschanny]

Roger, I would love to take a look at your recipe. Please post it! Thanks

[LouieAtienza]

If you want, you can just shellac your bindings and other elements that you don't want to stain with pore filler, and just use care later when smoothing out the pore filler.

[Rodger Knox]

The pores need to be sealed, but not necessarily completely filled before you start the TruOil, I typically brush on a couple of coats of 2# cut shellac, and sand back to wood. This does not fill the pores, but it does seal them. You don't have to sand, but I prefer the appearance of the oil directly on the wood. If you do sand, you need to get all the shellac off or it will show. With the pores sealed, the first 6 coats of TruOil will fill them. The first couple of coats will take a bit more oil to seal the wood, unless you left the shellac. Once it starts to shine a little after it dries (usually 3 or 4 coats), you can use less oil. I put the TruOil on very thin, at least 4 hours between coats. Every three or four coats I'll let it dry 24 hours and level sand, starting with 400 or 600 grit, and working my way up. When I get 16 to 20 coats, and have level sanded with 1000 grit, it's almost done.

The last coat has to go on perfectly, and then I'm done. I don't sand back after building the finish as is typically done with a nitro finish. This method produces a "soft gloss" which I prefer over the appearance of nitro.

I've found it works better if you stretch it out, there's less shrinkage if you allow more drying time. I'll frequently wait 3 or 4 days to sand back, 24 hours is a minimum. I usually take at least a month, sometimes six weeks, to do a finish. It's probably only 4 hours of actual time spent, and can be done in a week, but there will be some shrinkage, similar to nitro. Nitro is sanded back, and you can also do that with TruOil, but I wouldn't advise it. It's thinner than nitro, and getting it thick enough to sand back would take 40 or 50 coats.

Do NOT wetsand at any point after you start the oil, use dry paper on a block. Wetsanding will usually guarantee witness lines.

[jessupe]

There are some pretty good vids on utube going over grain fill....I think using pumice, shellac and alc, gives the best look personally...You can apply a slightly thinned zinnser seal coat wax free shellac coat{ sealer} then one more straight from the can...then do the pumice rub ie. cloth ball, dab of shellac, dab of pumice, dab of alc, then rub out and repeat. This makes a nice base for top coats...For a wood filler sand and finish, I think that Timbermate from down under has the best grain fill capabilities compared to others, but this can be labor intensive and potentially dangerous to the instrument if over aggressive sanding is done, Timbermate dries very hard and takes quite a bit to level it ...With pumice filling, beyond understanding the technique, the most important thing is your "ball" and how and what you make it out of...erasers can be good backers for getting into nooks and crannies.....good luck..Jess