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Main Boards => The Bowyer's Bench => Topic started by: Roy from Pa on June 10, 2010, 09:16:00 PM

Title: Need suggestions about removing Spar
Post by: Roy from Pa on June 10, 2010, 09:16:00 PM
I made my first takedown glass bow a while back. I sprayed it with Spar 10 days. I could not get a wet coat going, it was coming out of the gun too thick. So I ended up laying too much spar on it. It's been 10 days and when I try to sand it, it's still gummy. I need to get this bow back down to bare glass and wood so I can start all over. Any suggestions? Thanks, Roy
Title: Re: Need suggestions about removing Spar
Post by: No-sage on June 10, 2010, 09:32:00 PM
Cabinet scraper followed by mineral spirits.
Title: Re: Need suggestions about removing Spar
Post by: greyhawk39 on June 10, 2010, 09:40:00 PM
Acetone will take it off,make sure you wear thick rubber gloves.
Title: Re: Need suggestions about removing Spar
Post by: Roy from Pa on June 10, 2010, 09:47:00 PM
I tried mineral spirits, did not touch it. Will try the Acetone, thanks.
Title: Re: Need suggestions about removing Spar
Post by: Mike Most on June 10, 2010, 10:43:00 PM
I think I used 150 grit paper on mine when that happened, then had to go back up the scale with 220, 320 and 400.

Good Luck
Mike
Title: Re: Need suggestions about removing Spar
Post by: rainman on June 11, 2010, 12:15:00 PM
Is it Tacky over the whole bow or just the riser?  If it is just the riser what kind of wood is it?
Title: Re: Need suggestions about removing Spar
Post by: SteveR on June 11, 2010, 04:29:00 PM
Rainman may be right.  Some rosewoods will not take spar varnish without several thorough coats of shellac sealer underneath.  It will stay tacky forever because of the oils in the wood.  Cocobolo is notorious for this and several others as well.  

I still think the only good way is a good 'ole cabinet scraper and elbow grease and resand.  

BTW, spar varnish is particularly tricky to spray.  It can be done but takes experience and knowing how much mineral spirits to thin with, etc.  And it still takes a long time to dry properly.  Always seal underneath with clear shellac.  

Thats just a bunch of ideas from a luthier of about 15 years who specializes in varnish finishes.

Best of luck.
SR
Title: Re: Need suggestions about removing Spar
Post by: Roy from Pa on June 11, 2010, 05:11:00 PM
The entire bow is gummy. The riser is Diamond wood from Binghams.
Title: Re: Need suggestions about removing Spar
Post by: Art B on June 11, 2010, 08:02:00 PM
Now what how you gone and done now Roy! Hey, I've had finishes gum up from using poor quality tack rags. You use something like that? Got mixed up once and used paint brush cleaner (not thinner) that really gummed a finish up. I just scraped/cleaned with mineral spirits w/steel wool and sanded for a redo. Hope you get things straightened out. Good luck. ART
Title: Re: Need suggestions about removing Spar
Post by: Roy from Pa on June 11, 2010, 10:05:00 PM
Ya know, the paint scraper might work as I can just scrape it off with my thumb nail now. Might try a different finish the next time around. Any suggestions on a good spray on finish? Art, it prolly was a cheap tack rag. Gotta blame it on something.
Title: Re: Need suggestions about removing Spar
Post by: greyhawk39 on June 11, 2010, 10:23:00 PM
I use automotive clear coat dries in 15 minutes rub with a cloth and give it another coat.Mim wax semi gloss is good aswell and have had good results.
Title: Re: Need suggestions about removing Spar
Post by: Roy from Pa on June 12, 2010, 10:20:00 PM
What does rubbing it with a cloth do?
Title: Re: Need suggestions about removing Spar
Post by: greyhawk39 on June 12, 2010, 11:19:00 PM
I use the cloth to take the pebbling off the  limb surface,it cleans the finger prints off the bow at the same time. That might show up on the next coat.. I tried a buffer and the wheel wasn't able to get into the contours of the risers.