Wood filler question

[pjones]

So i have gotten one of the grizzly industries mandolin build kits and i need to know one thing that I am lost on. It states to use wood filler on the back and sides of the body, what kind of wood filler can be used? Can a plain clear filler from minwax be used or is it something special made for guitars? i know that stewart mcdonald has the colortone brand but i am curious if there is something else that can be used.
thank you

[hardryde_mando]

I think you might be talking about pore filling, which is the final step before finishing the instrument. You can use regular wood filler (mixed with water, roughly to the consistency of honey). If you are going to be french polishing, you might want to consider using pumice instead.

[pjones]

well in the manual it says to do the filler before dry fitting the neck?
http://grizzly.com/images/manuals/h5966_m.pdf
this is the first time i've done a project like this. so its all new to me

[Hans]

I don't believe I would fill the pores before gluing the neck on. You really want a wood to wood gluejoint especially with a joint like that. Make sure you get a very good joint with good squeeze out on the glue as this is a rather poor joint for a neck/body.
I would guess the neck and body to be mahogany as most of us don't use wood pore filler on maple as the pores are closed.

[Bill Snyder]

... You can use regular wood filler (mixed with water, roughly to the consistency of honey)...


Make sure if you are mixing water with wood filler that the filler is water based. I have never had any water based wood filler.

[Bob Aliano]

I used a water-based filler from Woodcraft Supply that worked fairly well. Try to get a filler that matches the wood color to eliminate streaks in places where the grain is wide. The first one I tried was called mahogany but was far too red. Smear the filler on diagonal to the wood grain and let it dry completely before you sand. Mahogany might require a second filler coat because of the loose grain.

[dunwell]

well in the manual it says to do the filler before dry fitting the neck?
http://grizzly.com/images/manuals/h5966_m.pdf
this is the first time i've done a project like this. so its all new to me

Hmm, interesting that they do it that way. Usually, as others have mentioned, grain fill is a finishing step. But other than the sanding to fit the neck the body really is ready to finit and finish at that point. I'm taking a WAG here that they are wanting the grain filled to avoid any glue squeeze-out from getting in the wood when you glue the neck where it would later cause finish blemishes. But regular care and good hygiene in cleanup as you glue should be sufficient particularly if you use HHG or Fish Glue.

The only other reason I can think of for filling first is if your grain filler is colored and you aren't gong to be coloring the neck, then it might be to avoid getting any of the color on the neck. Again, good masking and care could avoid that as well. Still, I don't see that it will cause any problem if you fill first since you will be doing a sanding fit of the neck. You should get a good glue joint on that surface.

Having blathered all that, back to your original question of what filler to use. I have over time tried a lot of different things and have settled back to using an oil based filler of one type or another. This is a bother and more work to sand back, but all the gel fillers and water based ones I've tried tend to pull back out of the pores or not fill well one way or another even after multiple fills. A product, that I have not yet tried, called WonderFill has been recommended to me. I believe it is available from Rockler.

FWIW,
Alan D.

[Herb H]

There have been a lot of different fillers used for open grain wood (mahogany, walnut) the past couple of decades, but traditional filler is oil based and either dark for a dark finish or very light for a blond finish. The filler is applied to fill the grain, and that means across or on a bias with the grain. If you wipe it with the grain, your wipe will dig some of the filler out of the grain where you're trying to fill it. The filler is allowed to set, not dry, and then wiped off across the grain -- again, so as not to wipe the filler out of the grain. A rough cloth -- burlap is good or hopsacking -- works well. After the cross grain wipe off, the residue in the "pores" is allowed to dry hard and will not need a lot of sanding.

I can't imagine using a water-based filler, unless special measures have been taken to raise the grain repeatedly and take off the whiskers. Obviously from the comments some have used or are using some water-based filler, but it makes no sense from my experience.