Official Luthiers Forum!

If you can't get naphtha, then try "odorless" mineral spirits for removing waxes and oils.  That product should be widely available.  It just takes awhile longer to evaporate.

I don't know with any certainty that oil is the problem.  It's just a SWAG based on your description.

-Ben

[QUOTE=JohnAbercrombie] Martin-
Naptha is also 'lighter fluid' for cigarette/pipe lighters (Ronsonol here in
Canada- your brands are probably different)- check your 'smoke shop'.
Camp stove fuel can also be used - we call it 'Coleman fuel' over here-
'white petrol'??

Cheers
John
[/QUOTE]

Found the product at local hardware with help from PaulB. Its called
"Shellite" here in Australia.

Ive sanded back the back and given it a thorough clean with the Shellite.
Im currently pumicing areas where the pores are open before
commencing the french polishing. Wish me luck.

Martin,

I thought you were using z-poxy. If so you don't need to use pumice, the z-poxy will fill the pores.

_________________
Dave Bland

remember...

"If it doesn't play in tune...it's just pretty wood"

I've been using LMI's micro bead filler as the base for my FP for a while now and have had no problems with it whatsoever. Dries hard,  does not stain light purflings or inlays and sands flat cleanly.

Also is it possible that you are laying too think a coating of shellac down and the outer layers are drying quickly while the lower layers are remaining moist?

Sort of like a mud flat where the top layers craze as they have dried and shrunk where the underlying layers are still moist?     

I think this issue has scared him off the Zpoxy.

If as he said the Zpoxy had curred for days before he started boding I doubt that is his issue.

There has to be somthing else. Sure would line to se close up of the problem.

I know that LMI specifically specs the Micro Bead filler for FP.....is the Zpoxy designed for this, or just for other finish types?  

Micro beads just add thickness to epoxy. Zpoxy is a finishing resin epoxy. You could use micro beads with it if you wished but I do not.

I have use Zpoxy for 3 years now for all my filling, French polish Ktm9, Nitro what ever. I have some 10 guitars with French polish and Zpoxy fill. I have never had an issue with just straight Zpoxy.

[QUOTE=Dave-SKG]

Martin,

I thought you were using z-poxy. If so you don't need to use pumice, the
z-poxy will fill the pores.

[/QUOTE]

I used Z-poxy as a pore filler prior to start of french polishing. After a few
body sessions I noticed the cracking in the finish and sanded back to bare
wood, in the process removing some of the Z-poxy from the pores. Worried
about applying more z-poxy over shellac I opted to pore-fill using pumice
prior to re-doing the french polish. The problem re-ocurred which is why I
think trapped oil in the pores may be the problem.

When or how did oil get trapped in the pores when filling with Zpoxy? or pumice for that matter? Neither of these processes should use any oil. The Zpoxy contains no oil. and pumice fill I never use oil just the residual shellac in the muneca inner pad and alcohol added as needed.

OK just so someone does not get confused. i have said this many times and will again as needed. If you plan to use Zpoxy or any epoxy as pore fill. do the filling before any shellac goes on the guitar. There is issues with epoxy over shellac. but no issues that I have encountered with shellac over epoxy.

I doubt this is the problem here but the Idea of trapped oil in the pores with epoxy fill would lead me to think that if this happend som sort of shellac and oil were applied prior to Zpoxy filling.

Just for the record, I think the "Micro Bead" filler that LMI sells (yes I realize "microbeads" can be used to thicken just about any kind of material....) is acrylic based.

Yes most micro beads are. Was there an inference to this fact? Or just pointing out that they or acrylic.

[QUOTE=MichaelP]
I doubt this is the problem here but the Idea of trapped oil in the pores
with epoxy fill would lead me to think that if this happend som sort of
shellac and oil were applied prior to Zpoxy filling.[/QUOTE]

Hi Michael,

No there was no shellac or oil applied to the rosewood prior to applying
Z-poxy. The only source of the oil could have been the small amount of
oil I use when cutting back after a few body sessions. I may have gone
through to bare wood in a few places and got some oil into some of the
pores that way.

Cheers Martin

At last some progress. I stripped back to bare wood and did a thorough
cleanup with naptha (=Shellite for you Ozzies). Put on 3 wash coats of
shellac and then pumice infilled. After 5 body sessions theres no sign of the
crazing that was plaguing me so it looks like trapped oil in the pores may
well have been the problem. All a P in the A but a lesson learned. Im gonna
get the hang of French Polishing even if it kills me.

(pictures gravestone..."Martin F Turner....French Polisehd himself into the
grave")

[QUOTE=kiwigeo] Im gonna
get the hang of French Polishing even if it kills me.

(pictures gravestone..."Martin F Turner....French Polisehd himself into the
grave")[/QUOTE]

" . . . and he missed this pore here "

Martin - I'm glad that your crazy crazing is no more. Another result down to the instrument making guru Percy Verance

_________________
Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010

Way to go, Martin.  When you get it like you like it, we need some pictures.  Not of your sore arm, but of the guitar.  

_________________
Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars