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UV cure of nitro lacquer
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Author:  Fred Tellier [ Mon Jan 17, 2011 1:12 pm ]
Post subject:  UV cure of nitro lacquer
I was at the Gym this morning and had a what if moment as I walked by the tanning beds room, would a tanning bed be useful to accelerate the cure of Nitro lacquer. The only thing I hate about Nitro is the waiting time between last coats and rub out and I was wondering if anyone has tried using a tanning bed for this.

Fred
Author:  hanstrocity [ Mon Jan 17, 2011 1:35 pm ]
Post subject:  Re: UV cure of nitro lacquer
Fred,
I haven't heard of using tanning beds to speed the nitro curing process.

However, I have heard of lots of people using them for other reasons. I recall one guy that said he has used it to give a more aged look to a spruce top. I have also talked to a guy who uses one to get his hardwoods closer to the color they will be instead of the sometimes deceiving color they can be when freshly sawed.

Great question my friend. I look forward to hearing people's thoughts and the applications that some might have used UV light for.
Best regards,
Hans
Author:  John Mayes [ Mon Jan 17, 2011 1:41 pm ]
Post subject:  Re: UV cure of nitro lacquer
It's a pretty old trick. I learned this from Lance McCullom years back. I made a cabinet lined with foil, and put a few 3-4 ft florescent UV lights in it.

It does indeed give the top a aged look (which means you have to be more careful about sanding through). It speeds the cure time a little bit too. Maybe cuts off a week.
Author:  Alan Carruth [ Mon Jan 17, 2011 2:06 pm ]
Post subject:  Re: UV cure of nitro lacquer
UV speeds up some kinds of chemical reactions, so it's useful for things like varnish and polyester. Nitro mostly cures by solvent evaporation, so it's hard to see how UV exposure by itself would help. UV cabinets can get pretty warm, though, and that could make a difference.

Nitro is chemically unstable, and UV speeds that up. That's why it turns orange and crazes over time. Iirc, Frank Ford has a jar of nitro up on the roof aging and turning orange, to use for touch-ups. It doesn't have to be 'cured' for that reaction to proceed. I have to wonder, though: since it's the nitration that renders the cellulose soluble, and it's the nitrates that break down under UV, if the stuff would get less soluble over time.
Author:  John Mayes [ Mon Jan 17, 2011 3:03 pm ]
Post subject:  Re: UV cure of nitro lacquer
Alan Carruth wrote:
UV cabinets can get pretty warm, though, and that could make a difference.


I suspect that was a part of it. I know I made a door for the front of the cabinet and the firs time I used it I hadn't thought it all thew way through and it got so hot/dry in the cabinet it ruined a fingerboard that was attached to a neck. Totally curled it up, cracked it everywhere, Fret ends totally out, ect. I then removed the door and never had the issue again. I know if it was left in the box for too long (like for more than 3-4 days the nitro would become really brittle and crack. So it for sure made a difference. I found just 1-2 days int he box was more than enough to speed the cure time. Then if you let it sit the normal time (as if there were no box) before final wet sand and buff the nitro had hardened so much it because much more difficult to buff out. I ended up letting them hang in the box for 12 hours, remove sit a day, and then back in for 12 hours, and then let it sit for 2-3 more weeks and it was as if it had sat for 4-5 weeks.

In the end I think it's probably not worth it. The risk of messing something up, or discoloring a top you don't want yellowed, ect isn't worth the extra week or two you gain. It's too easy just to factor in that extra time when scheduling a build in my opinion.
Author:  TonyFrancis [ Tue Jan 18, 2011 3:34 pm ]
Post subject:  Re: UV cure of nitro lacquer
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