daveq Posted April 16, 2004 Report Share Posted April 16, 2004 I went to a finishing class last night and wanted to share some things that I learned (please correct me if you think I was taught incorrectly): One interesting idea the teacher brought up was the use of many types of finish on a single piece. The idea is that each type of finish refracts light differently. As you layer them, the finish will appear "deeper" due to the light refracting in many ways. This is something he learned from reading about Martin's (the guitar manufacturer) finishing techniques and from speaking with someone who worked for Martin. I'm not sure what options are available for something like a lacquer finish - maybe a shellac sealer coat and lacquer top coats - but I don't know what else could be thrown in? Any ideas? Another tip was something that I knew but don't always do. Skipping grits when sanding can lead to problems that won't be seen until the finish has been applied. You can skip grits but you need to spend more time sanding to get past the gouges from the previous grit. I believe wiping Naptha (spelling not correct) can give you a preview. Using "tack cloths" - he recommended that people make their own. Take a rag and put a little turpentine and a small amount of the finish that you'll be using and use that as your tack cloth. The rags must not contain any elastic (no socks, ...) - the elasticisors (spelling?) will get into the entire finish and really mess things up. Sanding vs. Scraping - From what I was told - the Japanese woodworkers do not like to use sandpaper at all. They try to use blades for everything. Obviously, a sharp blade will give a much finer surface than a high grit sandpaper. This one has me a bit skeptical though - I thought that the highest you really need to go with most finishes is 220 to 320. Any higher will not show through in the finish. Is this correct? If so, why bother avoiding sandpaper? I wish I thought of this last night. He was also a very big fan of Tru Oil. I saw several pieces with that finish on it and I did like it BUT - I don't know if it has as good of a look as something like lacquer. Any opinions on this? It seems too good to be true since it is extremely easy to apply. That's it for now. Just wanted to share some info - I hope you find some of it useful. If you have questions - I'd be glad to share any more info that I have and please say something if you think something here is not right. Dave Quote Link to comment Share on other sites More sharing options...
guitar_ed Posted April 16, 2004 Report Share Posted April 16, 2004 Hi Dave, Interesting thought on using different types of lacquer on a piece. Personally, I would be too scared to mix. But a little experimentation would not hurt. As for scrapers v. sand paper. I should think that paper is much easier to control and use. As for what grit to use, I use up to 600 grit on the wood, and much finer than that on the finish. And you are absolutley correct about skipping grits. It don't work so well. As for TruOil, or any oil, vs. a "lacquer" finish, it comes down to looks v. protection. There are various threads on the site address the issu. Though it does look good. Guitar Ed Opinions are like @@sholes. And I just showed you mine. Quote Link to comment Share on other sites More sharing options...
decalshopmike Posted April 16, 2004 Report Share Posted April 16, 2004 I'd be interested to know what multi finish things Martin have used ? As far as I know every large scale manufacturer mainly just uses solid paint lacquer ( tinted or clear ) and sprays it on with a gun in a big booth - its cheap, you can do lots at once, and doesnt involve fiddling around. I have used blades for flattening finish in the past, but it is very tricky and if the blade sticks or digs you can ruin the finish easily - it is quicker than using lots of grades of sandpaper though. If it helps, on plain wood I use 600 grit as a finish and have never had a problem with marks showing through, dont think I'd like to leave it done with 240 though before lacquering as it could still be pretty rough, especially on maple which you really want to get smooth before lacquering as it saves loads of blocking the finish afterwards. I think most people have their own finishing method they have come up with over time that works for them, and rarely do 2 people use exactly the same technique. Quote Link to comment Share on other sites More sharing options...
VanKirk Posted April 17, 2004 Report Share Posted April 17, 2004 I have plenty of control and can remove quite a bit of wood with a scraper. Especially when carving the top on my flamed maple project. As for scrapers on a finish I didn't know that they were used for that. I thought the small circular motions of sandpaper are what give off the high gloss look. I wouldn't think it would be possible with scrapers. But I don't have much experience with finishing. I do like the results I'm having with tru-oil on scrap. It seems pretty durable and after several coats it builds up pretty well. Quote Link to comment Share on other sites More sharing options...
MzI Posted April 17, 2004 Report Share Posted April 17, 2004 the difference between the sand paper and using a plane/scraper is that the plane will leave a smoother surface and give you a better gloss finish, with sandpaper the wood gets dulled and doesnt look as smooth MzI Quote Link to comment Share on other sites More sharing options...
Reaper Posted April 17, 2004 Report Share Posted April 17, 2004 Could one of you guys be bothered to do a tutorial on using blades for polishing? I'm really quite interested. Quote Link to comment Share on other sites More sharing options...
renablistic Posted April 17, 2004 Report Share Posted April 17, 2004 a few coats of tung oil under a clear coat always looks nice IMO Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.