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Hi All:

I posted this question over on mandolincafe, and I thought I would post it here too. Hope that is ok.

A quick question - have any of you used drywall mud as a pore filler? I saw this video by Robert O’Brien where he demonstrates the procedure.



It looks simple (and cheap!) enough. But, I was curious to hear from someone else who might have tried it before I slather it all over the walnut sides and back of my OM.

Thanks,
Eric

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Eric Northway
http://northwaystringedinstruments.blogspot.com/

"Sine Cerere et Baccho friget Venus" - Terence, Eunuchus, IV.v

Yes, I have used and do use it.

Mix in some white glue , and some pigment to match the wood and smear it on.

Anything that you can shove into the pores of the wood and stays put is a valid pore filler.


Blessings
the
Padma

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Audiences and dispensations on Thursdays ~ by appointment only.


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I've used it (the dry powder, not mixed with water). I do not mix it with glue either, but use it like like pumice with shellac to create a slurry to fill the pores.

Pumice works much faster and isn't much more expensive, so I use it.

-jd

Thanks all for the responses. Food for thought.

Padma - what is the benefit of the glue? Similar to using epoxy? And, how much do you use?

_________________
Eric Northway
http://northwaystringedinstruments.blogspot.com/

"Sine Cerere et Baccho friget Venus" - Terence, Eunuchus, IV.v

Eric-
I'd certainly trust anything Robbie has to say about finishing.
You may have everything you need 'on hand'. If not, by the time you buy drywall mud and dye/pigment (what was Robbie using?) it might be almost as cheap to buy something similar, pre-mixed (and tested) from one of the luthier supply houses.

However, it is fun to experiment.
A trip to the lumberyard to pick up a walnut board for testing your pore-filing and finishing plan would be a good investment. (For small tests, the offcuts from the back might do.)
If you have light figure or sapwood in your walnut, keep in mind the effect that the black/dark pores will have on the final appearance.

Cheers
John
PS- Did you notice the large air filter next to Robbie's bench? After 10 sec of sanding you will understand!

I would not call it quite similar, other than again..."anything you can shove into the pores that stays put is a valid pore filler" get it?

I use various grades of dry wall compound and polyurithane and or white glue or hide glue and some times add colourant for various purposes, from pour filing to gesso for canvases.

As far as "how much" well "too much" is Just enought in my book. You see Duh Padma don't measure anything...go by " if it feels good - do it" ...them some times me just do it anyways.

But to answer your question.....

mix up 3 or 4 batches in dixie cups with various strengths of glue, take a good size piece of scrap wood and smear the stuff on, along with some mud with no glue it it...let them all dry and then sand. Then you will know what you like and what you don't like.

Regarding the "amount of dust" Ain't gonna be all that much, but I hear tell that sanding down the filler with out a roof over head for some strange reason envokes mother nature and her gentle breezes will solve the dust situation for you.



Padma

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Audiences and dispensations on Thursdays ~ by appointment only.


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If you do this - does it turn clear - and no need to dye it ? The powder is white - so if it does not clear - wouldn't that turn walnut grey ?

Robbie - any need to dye it for maple ?

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It's this new idea from recent decades that everyone gets a participation award. - MUX

Oh yes most definatly, The pore filler must be died purple or bright blue when
filling non porous woods like maple. And remember to add the ground up epoxie past and a bit of cement powder just to make sure it stays put inside the pores.




Padma

_________________
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Audiences and dispensations on Thursdays ~ by appointment only.


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ok - I am editing my post now....

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It's this new idea from recent decades that everyone gets a participation award. - MUX

If the pores are small and wood is light, it is sorta clear. Slurrying up with shellac you get lots of wood fibers and shellac incorporated into the mix so it sort of auto-matches to the finished wood color (like with pumice which is also grey)

-jd

Thanks for all the info folks! I appreciate it.

_________________
Eric Northway
http://northwaystringedinstruments.blogspot.com/

"Sine Cerere et Baccho friget Venus" - Terence, Eunuchus, IV.v