Official Luthiers Forum!
http://www.luthiersforum.com/forum/

FP over varnish?
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=21451
Page 1 of 1

Author:  Pat Foster [ Fri Mar 13, 2009 2:36 pm ]
Post subject:  FP over varnish?

I've been experimenting with FP over varnish. Seems there was mention of it here awhile back. Anybody remember?

You may ask why.

Behlen's Rock Hard Varnish is a lot tougher than FP, but can yield witness lines (I brush it on), which are covered by the FP. FP is easily reparable. A likely future customer loves the look of FP (so do I) and may want it on a gigging guitar. So far, no adhesion problems, sanding the Behlen's with 320 under the FP. I building with the varnish, sanding back, then 3 sessions with FP. Managed an invisible repair where I gouged through the PF and varnish down to wood, built it back up with varnish, then FP. Can't see it.

Any input? Ideas? Strawberries?

Pat

Author:  Michael Dale Payne [ Fri Mar 13, 2009 4:22 pm ]
Post subject:  Re: FP over varnish?

Pat'
Shellac will stick to darn near any thing with no issues. that said there are a few things that will not always adhear to shellac real well but most finsh products will. It would be hard to think of somthing shellac would have a problem adhearing to.

Now what I think of FP over varnish? Well for me it would not be my thing because I just don see an advantage.

Author:  David Newton [ Fri Mar 13, 2009 4:43 pm ]
Post subject:  Re: FP over varnish?

Hi Pat.
I'm just now experimenting with a test board of mahogany with the schedule:
stain/stained pore filler/seal with shellac/ build up with behlens rock hard/ fp shellac final gloss.
I stained and filled before the sealer for a very dark color.

This was a schedule given me by a full time builder who is very busy, and needed a faster system while still avoiding a spray system and nasty chemicals. He is using Pratt & Lambert #38 varnish, claims witness lines are not an issue.

Big issue with varnish: dust. Lots more sanding between coats. Varnish needs to dry very well before the final FP gloss, probably several weeks, to avoid "lean over fat" cracking in the future.

Straight-up French Polishing has a lot going for it, I don't think I'll abandon it at this point. It's clean and simple.

Author:  Pat Foster [ Fri Mar 13, 2009 4:54 pm ]
Post subject:  Re: FP over varnish?

David,

Your schedule is very close to mine with the exception of another seal coat of shellac after stain and before filling using LMI's water-based filler on mahogany. Luckily, intuition told me to wait two weeks after the last coat of varnish before FP given that the varnish was a bit soft before then. Thanks for the reply.

Pat

Author:  Pat Foster [ Fri Mar 13, 2009 5:02 pm ]
Post subject:  Re: FP over varnish?

Michael Dale Payne wrote:
Pat'
Shellac will stick to darn near any thing with no issues. that said there are a few things that will not always adhear to shellac real well but most finsh products will. It would be hard to think of somthing shellac would have a problem adhearing to.

Now what I think of FP over varnish? Well for me it would not be my thing because I just don see an advantage.


Michael,

I have read where shellac doesn't stick so well to very old varnish, but so far, I personally haven't seen anything it wouldn't stick to, and very well, I might add.

I do see an advantage when I ding the varnish on spruce with my fingernail, compared with FP on spruce. I've scraped finish off of tops done with Behlen's Rock Hard and FP. It's much harder to get the Behlen's scraped off than FP shellac.

Pat

Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/