[
QUOTE="HaMMerHeD, post: 17108573,
member: 57295"]Do you have a make/model on those sanding sponges?[/
QUOTE]
They are just standard 3M sponges you can find at most paint shops. They are the
preferred sponge for most shops I've worked in but for some reason I can never find them at Lowes or HD.
I use the super fine grit but even those are too rough when they are new. I like to use them to pre sand the body before I spray. Not only do the flexible sponges work great for that last bit of touch up sanding, it removes the sharp edges and dulls the grit. Once they are fairly worn I wash them out and save them for sanding between coats or after the final coat as I am here.
[
QUOTE="Ol'Bass'ead, post: 17109917, member: 49762"]Care to share the details of the finishing product?[/
QUOTE]
The finish I am spraying is a 2 part conversion varnish. The particular product is called Sher-Wood and is made by Sherwin Williams. Being a two part mix a catalyst is required as well. Its a fairly expensive initial investment as the catalyst is about 45$ a bottle, but I estimate will catalize around 10 gallons. A gallon of the varnish cost me a bit over 60$ but I found that I ended up saving a little bit over lacquer due to the higher build.
Conversion varnishes are not a common finish unless you work in high end woodshops. They are high solid finishes designed to build quickly. Its generally agreed that Xylene is the best solvent to use, though thinning is really only advised for the sealer coat(s). For years I have been spraying lacquer for my guitars and furniture and I would estimate that one good coat of CV is equivalent to 3 coats of lacquer once the finish dries. If you wait more than a couple of hours between coats it is required to lightly sand the previous coat for adhesion but if you spray one coat after another with just enough time to flash off it can be built up without sanding. One cool advantage is that blushing is just not an issue for whatever reason, so that's one less problem to deal with. I've found that it takes about 5 coats to build to what I want for a guitar and that takes about 2 hours or so. Another great thing about CV is that it cures fast and can be wetsanded and buffed in 24 hours or so.
Obviously all these positives will be balanced by drawbacks as well. Cleanup is much more necessary than lacquer because once the varnish is catalized there is a pot life of a couple days or so if you keep the excess in a covered container in a fridge. Left in the gun though, it will start setting up quite quickly and once it sets the gun becomes really hard to clean. I get around this by buying a 20$ gun from harbor freight and disposing of it once I finish that project. It sounds crazy but those cheap guns work quite well if you clean them properly before use. It's also important to monitor the temperature as it definitely needs to be sprayed at 65 degrees or higher.
So, if you only consider the final product it's hard to argue with the conversion varnish as it applies and cures much more quickly and the finish itself dries very hard and is quite resistant to chemicals. In the big picture though, CV is a more difficult finish to work with and things like proper gun setup can be much more touchy. Also keep in mind that I work 20 feet from one of the best finishers in Austin. I would probably have had much more difficulty without his guidance. I'm also not convinced yet that CV is quite as attractive as lacquer, I'll have to build a couple more to find out.
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