Official Luthiers Forum!

My big question is, is there any way to speed up the cure of varnish?

I am in a bit of a bind, and hope someone can help. I need to get two instruments finished, like right now. I have a festival coming up this weekend, and needed some lower cost instruments to sell, in this case dulcimers. I got them built, then put on the finish. I was goign to try a quick shot of lacquer, but after reading the thread on the SW varnish, I bought some. I tried it on a test piece, and also tried another called Tried & True varnish, which is a linseed oil varnish. Supposedly it is a natural resin varnish, based on a formula for coachwork dating back to 1850. Anyway, I tried the two, and the next morning, the T&T was drier than the SW. So that is what I used.

Now, two days later, the T&T is still oily to the touch. I am writing this on Monday night, and plan to put these instruments on my table at my booth on Friday. The instruments still feel a bit oily, and when you handle them, your hands smell like linseed oil. Not what I want.

According to the directions on the can, it should have cured in 24 hours. Tonight I tried heating the instruments with a heat gun, and noticed when the surface gets hot, it weeps. Tiny droplets of oil can then be wiped off.

I put the finish on bare wood, with no sealer coat. I did this to save time, since I am after a low price point with these instruments. Low as in less than $350, maybe even less than $300. So all I want for these is a finish that looks decent while giving some protection. nothing fancy. I think for my next batch of these I'll try poly, but for now, I've got to get these finished.

I am leaving them in the shop tonight with the dehumidifier running. It was about 79 degrees out there a while ago, so it will be warm and dry. I thought one possibility might be to apply some hard carnauba wax via buffing wheel to seal the surface.

Any suggestions? I'm not quite desperate yet, but may be tomorrow!

_________________
Phil

http://www.oleninstruments.com

"Those who tilt at windmills are only considered insane by those who can't see the dragon."

Finishes heavy in oils like linseed almost demand to be applied in several thin coats with plenty of dry time between. Shellac applied by brush or spray would have been a better choice for a fast , low cost type finish. You could try wiping off any excess oil with a clean rag dampened with mineral spirits, but I feel that will leave a blotchy looking finish at this point. Right now airflow is your best friend. Set up fans and get the air moving over the surfaces, hopefully you don't pick up to much dust and dirt in the finish.

_________________
Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Thanks Brian, but the strange irony here is that I was trying for something faster than shellac. My other instruments have hand rubbed shellac finishes, and they look nice. Not quite a French polish, but satin, with a bit of gloss. Very smooth, nice to hold. But they do take some time, it can take me several days to get one done, sometimes longer. And convincing customers that this finish is worth more than the standard one-coat shot of lacquer most use has been, well, difficult. Amazing to me how many balk at a $600 price for work with hand carvings, bindings, smooth joinery, proper setup for playability, and a nice finish. Last year at a show, I even had another builder turn his back to me to tell potential customers to ignore my instruments because they are overpriced. Yeah, I could hear him.

So when I read on the can that you put on a thin coat, wipe dry after one hour, then buff with steel wool after a 24 hour cure I thought I'd hit the jackpot. Especially after my test piece turned out well. And I have no doubt that in two weeks, it will look fine. Unfortunately, I only have two days. And since it soaked into the wood, I can't see a way to strip it and start over.

Did I mention how much I have learned by doing things wrong?

_________________
Phil

http://www.oleninstruments.com

"Those who tilt at windmills are only considered insane by those who can't see the dragon."

Heat lamps like the ones in a shower will help, I use them all the time in the winter. The auto finish industry has some specific bulbs, but the basic heat lamps from the hardware store will help. Not too close though, as you discovered, too much heat will be an issue, but the infrared light does help. YMMV and all that.
Rob

_________________
http://shastaguitar.com/
http://www.kalimbakit.com/
http://www.youtube.com/user/comfyfootgr ... ature=mhee
http://www.facebook.com/robert.renick.7

Sorry I didn't chime in earlier on this one.

Most oil-resin varnishes will cure a lot faster under UV light: some won't cure without it! I use this trick when non-drying oils in woods like Macassar ebony give me sticky spots in an otherwise cured film with the 'Rockhard' varnish I've been using. Usually a day or so in a foil-lined box with a few UV lights will harden it up. I'm told that this works because the UV creates ozone at the surface, which reacts faster than plain O2. The thicker the coating, the less useful this is, and I've found that if the first coat isn't hard, it won't harden up under a second coat, even when the second coat does harden. At some point down the roar you'll run your finger across the surface and it will all peel off: golly gosh-darn HECK!

These days they make those UV CFLs that fit in normal light sockets, so it's easy to rig something up.

Hey, thanks for the advice on this, now on to the next question. I did take them to the festival, they didn't sell. (Neither did anything else for that matter, this economy is not so good.) Anyway, toward Saturday afternoon we got a few sprinkles of rain. Not much, and I packed everything up before it all got wet. But, I noticed that each of these now has a raised spot where the rain drop hit this uncured finish.

I now have them sitting out in my spare room, with no deadline for the next step. So, what is best to do here? Not only is my finish less smooth than I wanted, it now has these little raised dots in the finish. Any way to sand this out once it cures, then cover with some lacquer or poly or anything else?

Thanks,

_________________
Phil

http://www.oleninstruments.com

"Those who tilt at windmills are only considered insane by those who can't see the dragon."

Al, are you talking UV bulbs or Infra Red heat lamps?

_________________
"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

I notice on their website they mention beeswax as an ingredient, that tells me the coating is most likely not very water resistant, much the same as natural shellac. Combine that with the lack of driers and this would appear to me to be a rather soft finish which will most likely make it a bad substrate for any type of harder finish like lacquer. It is also worth noting that in a test of 15 wipe on finishes conducted by Fine Woodworking mag a few years back that this finish was rated the worst of the bunch, with long dry times being cited as one reason as well as poor water resistance. To determine the best course of action from this point I would recommend finishing some test panels with the same process you used as closely as possible and spritzing with water, then you can try different solutions to see what can be done. Perhaps additional coats of finish may be all that is needed. Normally I would recommend to strip and re-finish with something better, but penetrating finishes based on linseed oil don't tend to strip very well.

_________________
Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Don Williams asked:
"Al, are you talking UV bulbs or Infra Red heat lamps?"

UV. Some years back I made some 'Fulton Varnish'. You heat and aerate turpentine to get a thick polymer, then cook that down to a resin (outdoors!). This is mixed with a drying oil, and further cooked to form the co-polymer, which is then thinned out with some more turps, and you can paint it on. It's a nice varnish, but not quite what Strad used. It will only cure under strong UV light. Fulton has no problems with that: he's a few thousand feet up in the Sierras, but we New England luthiers need a UV light cabinet.

Do you think sitting them outside will help? Right now we are having nice weather, with bright sun, clear skies, and mild temps (mid 70's.) Worth a shot?

Brian, I wonder about maybe putting the SW varnish oil over this stuff once it cures a bit. As was noted on another thread, that stuff is linseed oil based, so it might be compatible. Or is that just going from bad to worse?

Thanks for all the ideas,

_________________
Phil

http://www.oleninstruments.com

"Those who tilt at windmills are only considered insane by those who can't see the dragon."

Once you are outside the manufacturers recommended applications the only way to be sure is to run some test panels. Better to find out if it really works or not on some scrap rather than the actual item. My initial guess is that the two finishes would bond satisfactorily but how it may look is an unknown, could wind up blotchy or hazy, could look great, the only way to know is to try it.

_________________
Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/