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Spraying Shellac?
http://mowrystrings.luthiersforum.com/forum/viewtopic.php?f=10101&t=54604		 Page 1 of 1
Author:  Slim [ Wed Dec 08, 2021 11:38 pm ]
Post subject:  Spraying Shellac?
Anyone ever spray shellac with a hvlp setup. I have padded shellac, brushed shellac, and sort of French polished with shellac but never sprayed it. What got me thinking about it besides liking shellac was reading about some furniture guys doing it so I thought I would see if any of you guys or girls are doing it or have done it with instruments with success.
Author:  SteveSmith [ Thu Dec 09, 2021 7:28 am ]
Post subject:  Spraying Shellac?
I have sprayed it with my EGO LVLP gun but only as a seal coat. Worked fine.
Author:  jfmckenna [ Thu Dec 09, 2021 8:28 am ]
Post subject:  Re: Spraying Shellac?
I've been wondering the same thing but with Royal Lac.
Author:  SteveSmith [ Thu Dec 09, 2021 9:20 am ]
Post subject:  Re: Spraying Shellac?
I’ve sprayed 2 guitars and a mandolin with Royal Lac. In all 3 the finish crazed after a few months. There are some threads here that go into it. Mine failed because I put it on too thick and did not leave enough time between coats. The manufacturer can provide you with a good spray schedule. I switched to french polishing with Royal Lac and am happy with that.
Author:  Slim [ Thu Dec 09, 2021 10:57 am ]
Post subject:  Re: Spraying Shellac?
I was told when spraying the bug juice Shellac it is very sensitive to humidity much more so than nitro. Don’t know if that’s valid but I guess it makes sense given shellacs normal response to moisture. But man if you could ever get setup for good results with it it would be a dream with its fast drying characteristics along with the benefits of spraying.
Author:  Clay S. [ Thu Dec 09, 2021 11:58 am ]
Post subject:  Re: Spraying Shellac?
Chuck Tweedy who sometimes participates on the MIMF forum would spray some base coats and then French polish on top of them. You might inquire there and see if you get a response.
From what I've seen with people spraying furniture, shellac doesn't seem to "hang" that well on vertical surfaces and can make a sticky mess of the spray gun (and overspray area) if not cleaned up reasonably quickly.
Author:  Slim [ Thu Dec 09, 2021 11:21 pm ]
Post subject:  Re: Spraying Shellac?
When it comes to Royal Lac what do you think about in terms of how it compares to standard dewaxed Shellac or other popular instrument finishes? I understand it is claimed to be more durable, more water resistant, and probably other things I have forgotten.
Author:  TimAllen [ Fri Dec 10, 2021 2:01 am ]
Post subject:  Re: Spraying Shellac?
I haven't followed recent claims about Royal Lac but when I purchased some a few years ago the maker said it was more resistant to sweat but did not claim it was more durable in other ways. In my experience it is a very nice looking finish, but no more scratch or dent resistant than regular shellac. I have stopped using Royal Lac after seeing photos of it failing after some period of time, which has been blamed on wet sanding between coats. Regular shellac also looks great and I know what to expect from it, though I wish it were tougher. I have not sprayed Royal Lac or other shellac-- just brushed or padded base coates, then French polished. Spraying would make sense if you wanted a fast, thick build, but I don't see why a thick film of shellac would be better than a thin film. It might be more prone to showing wear.
Author:  jfmckenna [ Fri Dec 10, 2021 8:19 am ]
Post subject:  Re: Spraying Shellac?
I have only used RL on about 5 or 6 now so I cannot say anything for sure yet about how resistant it is and so on. But I do like the way it looks padded on and then buffed out. I have heard not to wet sand between coats but I actually still have a can of it from years ago that has wet sanding on the instructions. The most recent one I bought does NOT have the same instructions so it must have been something they discovered in due time. I think that issue is ironed out but time will tell.
Author:  SteveSmith [ Fri Dec 10, 2021 8:29 am ]
Post subject:  Re: Spraying Shellac?
If I remember correctly Vijay said wet sanding was ok but only after the Royal Lac has fully cured. Putting water on the finish too soon causes problems. Since most of us tend to be impatient with the finishing process (all processes?) it was probably a good idea to remove that from the instructions.
Author:  doncaparker [ Fri Dec 10, 2021 11:15 am ]
Post subject:  Re: Spraying Shellac?
Wet sanding between sessions was recommended earlier on, before some folks discovered the hard way that the water might cause problems prior to the finish fully curing. If you take a look at Robbie O'Brien's video regarding the original formula, the warning regarding wet sanding has been superimposed on the video, but he still wet sands between sessions in the video. It didn't cause problems for Robbie, but it might for someone else, so it's best not to tempt fate.
Author:  Slim [ Fri Dec 10, 2021 11:24 am ]
Post subject:  Re: Spraying Shellac?
Something that I have never done but believe others have done is to lay down a good film of shellac not just a sealer but a nice film finish then place a top coat or 2 over with nitro to but I’ve never done it so I can’t say if it’s good or bad.
Author:  Bryan Bear [ Fri Dec 10, 2021 5:14 pm ]
Post subject:  Re: Spraying Shellac?
SteveSmith wrote:
If I remember correctly Vijay said wet sanding was ok but only after the Royal Lac has fully cured. Putting water on the finish too soon causes problems. Since most of us tend to be impatient with the finishing process (all processes?) it was probably a good idea to remove that from the instructions.


More specifically, he said not to wet sand until after it has fully cured meaning at least 30 days. I only bring this up because someone reading in the future could confuse "dry" with "cured." When it comes to shellac (and Royal-lac) it can seem like it is totally done after just a few days and even be dry to the touch in a few mins. After about 30 days, Royal-Lac changes. I'm not smart enough to say how, but Vijay is. It becomes, more or less, impervious to water and alcohol (something that never really happens with shellac). The advice to not wet sand applies to not using water until that change has had a chance to happen.
Author:  bftobin [ Fri Dec 10, 2021 5:24 pm ]
Post subject:  Re: Spraying Shellac?
I have heard about a well known classical maker in California who uses shellac, alcohol and acetone (no oil) and can finish a guitar in one day. With both acetone and alcohol evaporating so quickly, it may well work. Don't know if it would work with Royal Lac.
Author:  Slim [ Fri Dec 10, 2021 5:29 pm ]
Post subject:  Re: Spraying Shellac?
bftobin wrote:
I have heard about a well known classical maker in California who uses shellac, alcohol and acetone (no oil) and can finish a guitar in one day. With both acetone and alcohol evaporating so quickly, it may well work. Don't know if it would work with Royal Lac.



French Polish correct?
Author:  doncaparker [ Fri Dec 10, 2021 5:30 pm ]
Post subject:  Re: Spraying Shellac?
I think that builder is Brian Burns. The method is outlined in the Gore/Gilet building book. I haven’t tried it yet, but I’m curious. I think Alan Carruth here on the OLF has talked about it, too.
Author:  Pat Foster [ Fri Dec 10, 2021 9:09 pm ]
Post subject:  Re: Spraying Shellac?
A builder friend sprayed RL for a while. I did the final power buffing on a few of them and saw great results. He had to stop spraying on doctor's orders due to lung issues brought on by poor protection in his shop.

I still have the first guitar I used FP RL on, 6 or 7 years ago, if I recall. It still looks great. A few years after its completion I made a puddle of water on it for three hours and it left no mark. Everclear barely touched it, but not nearly as much as it would if it were plain shellac. I've used it on 8 or 10 guitars since, with no problems reported. Knock on well . . . . wood.
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