Joint Compound for Pore Fill

[spindlebox]

I read somewhere that joint compound can be used as pore filler.  Anyone here use it?  Tips appreciated!  

[Bizman62]

I've read that too and to be more precise, it was used for guitars.

I've never used any actual pore filler other than oil slurry, the poly I've used has been thick enough to fill any pores in the woods I've used. Mahogany may have bigger pores than the alder I've mostly been using, then again when testing a "new" 2k poly a single coat could have been used as the final finish on a block of mahogany featuring almost every imaginable angle.

There's valid reasons why joint compound is a good pore filler: It's gypsum based which makes it solid and stabile. Also it's a bit porous which makes paint grip onto it. And it's easy to sand. Obviously it suits best on items that will be painted but the porosity may even make it take dye for interesting effects  - which reminds me of someone using ebony dust and glue slurry for filling the pores of a pale ash body. For such adventures testing with scrap pieces is highly recommendable!

Finally, if a spackle of any sort sticks to wood and is intended to be painted, it can be used on guitars as well. Painting a guitar is not different to painting a car or a piece of furniture.

[spindlebox]

This is great!  Thank you!

 

[henrim]

I've used pumice. Which is powdered volcanic rock. If applied to wood with e.g. shellac it can be used as grain filler. Pumice can also be used for many other different purposes. If mixed with paint you can use it as joint compound. The nice thing is that you can mix it with the paint you are painting with and you can easily vary your filler's viscosity. You can also use it as abrasive or cleaning agent.

[mistermikev]

I think you could probably use just about anything... but is it a good idea?  I don't know but I would lean towards 'not'.  the whole idea of bondo, spackle, joint compound is that it drys fast and is easy to sand.  easy to sand often translates to brittle/light.  I imagine that could lead to a 'soft spot' in your finish down the road.  I try to avoid any filler at all costs... would rather do a bit more work in terms of spray and wet-sanding iterations to end up with a finish that is consistent throughout. 

that said... on ash you almost have to do some kind of filler or you'll be spraying forever... so in those cases I've used some filler that was recommended on a mandolin site.  it drys back and shrinks quite a bit which suggests to me it may be harder... but alas more work as I find myself re-applying several times.  I'm leaning towards some quality epoxy next time I have to do a gloss on ash.  ymmv.