MIMF

My current project has to have a nitrocellulose finish. Not acrylic, not poly, not waterborn: nitro. I have no spray equipment nor the budget to acquire it. I had thought to use rattlecan Deft, but the recent thread about Deft put me off that idea.

So what suggestions are there (incl. brands and suppliers)?

Mohawk sells rattle can nitro as does Reranch. I haven't used either but many folks here have.

Not knowing were you are makes it difficult to advise you when and how.

The basics would be to shoot outdoors, warm up the guitar and warm up the rattle cans in a dish pan of hot water.

David King wrote:Mohawk sells rattle can nitro as does Reranch. I haven't used either but many folks here have.

Not knowing were you are makes it difficult to advise you when and how.

The basics would be to shoot outdoors, warm up the guitar and warm up the rattle cans in a dish pan of hot water.

Thanks, David- although "warm" and "outdoors" don't really compute here in November!

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What about brushing nitro- or is it just the road to suicide?

Find someone with a spray booth or warm up your garage and risk blowing yourself sky high.

Watco makes a brushable lacquer and I know one reputable guitarmaker who has used it and was pleasantly surprised.
http://www.rustoleum.com/product-catalo ... ood-finish
If you can vent effectively to the outside you can probably brush it on. I'd look around for someone local with the gear and the experience and pay them to do it right. Figure $175-$450 as the going rate.

I believe Minwax also makes brushable lacquer. Brushing lacquers tend to have retarder added and lower solids content to help with flow out. If you look up the MSDS you can get an idea of the nitrocellulose content. Cooler weather can sometimes help with flow out. I would have the lacquer, the guitar, and the environment you are doing it in, at about the same temperature to avoid blushing or air bubbles.

I've had pretty good luck with this stuff:

http://www.woodcraft.com/Product/149254 ... rosol.aspx

They also make a vinyl sealer to go with it.

OK, the game just changed. I have the use of a compressor now, and a gun if I want it (or I may buy a Harbor Fright HVLP gravity gun).

Now- what pressure and cpm should I be using? What nozzle size?

I use about 40 PSI at the gun, works for me. I know other folks think less is better but that really depends on your gun, viscosity you are spraying, and the material. You will have to practice a bit with fluid delivery which is usually the adjustment at the very back of the gun head and is usually just a trigger stop so the needle is restricted from opening and allowing more fluid, air delivery (often a small knob at the bottom of the handle) and fan, which is air that comes in from the sides to spread the cone of spray into an oval to varying degrees.

Not all guns have the same adjustments but generally they provide some control of the delivery and pattern. It's not rocket science but it does take some practice to get up the learning curve. The folks at paint stores are usually very helpful with suggestions and guidance, especially if you buy your finish from them.

You need to get enough delivery to get a wet coat but not a thick and saggy coat. Just wet, and move on. Your next pass should be aimed at the edge of the previous pass so you are overlapping half of the spray pattern. Hold your gun about 10 inches away from the surface, too close gets more runs and tiny bubbles in the finish, and too far away gets dusty rough surface that can contribute to orange peel if oversprayed wet. So make the surface just wet and move on. This avoids the runs and sags, and a thin coat will dry much faster so it can be sanded sooner and get another coat on.

Thanks. Any recommendation on nozzle size?

Harbor Freight has high pressure Jamb guns for sale for $13. I bought a couple because the cup fits the (cheap) jamb gun I already have. The HF guns work okay when fitted with the $4 regulator they sell. They also sell a little gravity feed detail gun ($12) that would be great for doing bursts.
You can spray brushing lacquer if you thin it, but Mohawk instrument lacquer will give you more solids per coat and should have more plasticizers to give a less craze prone finish.
I adjust the pressure down to minimize overspray. The smaller guns seem to work well at 20-25 psi (sometimes less). High pressure guns get a bad rap, but if adjusted properly can do a better job of atomization, and with the smaller guns, pretty good transfer rates. Most of us are not satisfied with an "as is" finish and sand and buff what comes off of the gun, so a less than perfect result is O.K.

For nitro, nozzle size is not critical. It is a thin easily sprayed finish - one reason it was popular. I just use the set up that comes with the gun.

Got it. The reason I'm thinking HVLP (also not expensive from HF) is that allegedly they waste a lot less material than HP guns. And, yes, I realize that the sprayed finish is just the raw material for sandpaper and elbow grease.

Even given the sandpaper and elbow grease, you can get a much better job if you can put the finish down evenly off the gun. My finish jobs improved a lot after I got a decent gun. I still have the old cheapy. I may get it out next time I do a session and see what I can get out of it knowing what I know now. The old one wouldn't atomize very well. The remains of the orange peel finish still showed even when the finish was leveled and polished. The good gun leaves a finish that tempts me sometimes to not level and polish (but I always do).

A cheap gun will give a better finish than a brush, a good gun will give a better finish than a cheap gun. A small jamb gun will give a tighter pattern than a full size gun and push out less material and may offer better control. A cheap hvlp conversion gun generally uses more air than a conventional high pressure gun and may not give a better transfer rate. There are things you learn by doing, and the cheap HF guns are an inexpensive way to get your feet wet. At my level of production (Hobby building) they are all I need.