Help With A Rattle Can Finish?

[The Posh Mushroom]

Hello everybody, I just wanted to ask for some help and advice. Maybe some of you have seen my project, I've posted once or twice about it. Anyways, it's a sort-of partscaster, in that I bought the neck, but made the body. Speaking of that body, it is roughly inspired by Jerry Garcia's Tiger and/or Rosebud guitars, made out of a StewMac Knotty Pine Blank, but with strat wiring, and a side jack, Tele-style. (always hated the front jacks for some reason, not really sure of its the look or the feel, or them constantly tugging at you just a bit when walking away from the amp.)

Anyways, I've been finishing it recently, first with a thin coat of sanding sealer, and then lacquer, all from rattle cans (also from StewMac). It has started to drip horrible on the front and a little on the sides. First off, how can I get rid of these specific drips? I would think sanding, but do I need to sand to bar wood, or just until it's flush? Also, approximately what grit should I be using to do this. Secondly, how can I not get drips in the future. Thirdly, how many coats should I do, if I then want to sand/buff it to a mirror finish? (or as close as I can get to it :18. Ill attach pictures down below....

Also, for the future, is there any good way to protect this, case wise? I don't know of any cases that would give enough support that I would not have to worry about the horns, as they get rather thin... and any custom case would be way out of my budget. I thought about maybe a nicely padded gig bag, any suggestions? If anyone has a good solution, please relay that to me. BTW it's about 13 inches wide at the widest point, (the body curves), and 17 inches from the large horn down, and it will have a normal Stratocaster neck with the accompanying scale length.

Well thanks for reading all my blabbering and (probably) stupid questions. Also, as you can probably tell, this is my first guitar. (do with that info as you will)

 

[MikeRocker]

Re: Help With A Rattle Can Finish?

Based on my experienced, and I have finished and assembled 7 guitars, I would say sand those runs starting with 400 grit paper, and use something for a sanding block. I wrapped the paper around a sanding sponge myself, but almost anything firm will do. Also, wet the paper with mineral spirits before you sand, and then re-wet often during the process. You do not need to sand down to bare wood, just until the (former) runs are flush with the rest of the finish. If the 400 is taking too long, you can go try successively more coarse grits - 320, 240, etc. But always start out easy!

And then, spray much, MUCH less. Each coat should be very thin, and should never come close to running like that! That is why a nitro finish requires a lot of patience, it's all about building up very thin coats, and the process takes quite a while. Always err on the side of spraying thinner vs. heavier. I usually spray a thin coat, let it hang for about an hour, then do another. I estimate I would usually do 4 or so coats a day. Spray super thin, then if it seems dry in about 15-30 minutes, you can spray again, SLIGHTLY heavier. Use a light touch with the spray...if you go over the whole body, and it seems pretty dry, make another pass or two. The day after spraying 4 or so coats, I sand it down with 400. The idea is that you gradually build up the finish, then knock it down so that it's even, then start up again...and every day, it gets a bit thicker. After doing this for a while, you have enough finish on it so that it can cure for a month, then you can sand it up through 2000 grit (at which point it will be totally matte), then use buffing compounds to polish it to a gloss. Ain't gonna lie, the first time you see your reflection in the finish is pretty awesome...

Good luck!

 

[The Posh Mushroom]

Re: Help With A Rattle Can Finish?

Thank you so much. I have a sanding block thing that i have been using, so I will do that, and also spray a lot thinner. About how many coats would you recommend, including sanding it down after each day of spraying?

 

[MikeRocker]

Re: Help With A Rattle Can Finish?

My pleasure As far as coats, I don't think that I can give you a specific number, but I would say A LOT! Probably a couple of cans worth, over several weeks. Are you doing a color? The reason I ask is that if you don't spray enough coats, you can end up with a sand-through...which is about the worst thing ever after you think you have finished (no pun intended) all of your spraying, and you have waited a month for the nitro to cure - suddenly, you see a wood-colored spot through the nice color, and your soul is crushed...

Have you checked out Reranch? He has some great, specific instructions posted for free...start by checking out the 101:

http://reranch.com/basics.htm

 

[Pontiac Jack]

Re: Help With A Rattle Can Finish?

Also make sure you apply the paint in the best possible weather conditions. If it's too cold,you will get runs,crazing,orange peel,patchiness, all sorts of nasty stuff. If it's cold you can bring the paint up to temperature by standing the can in warm water for a couple of minutes. Warm water!! Not boiling water and never in a pot over a flame. And always shake the crap out of that can!!! A couple of minutes at least.

Cheers,PJ

 

[Taz Rules]

Re: Help With A Rattle Can Finish?

Agree with the advice already given. I'm used to working with automotive paints, but the same theories apply to all paint, including rattle cans.

A few other things I would add...
Wear a mask. Paint coats the inside of your lungs exactly the same way it coats your guitar body.

Spray in a warm room. Warmer the better. Paint flows and dries best at 80 degrees f.

Thin coats. I know this was said already but it bears repeating.

FWIW, you can build a cheap downdraft spray booth using 5 sheets of plywood, furnace filters, a shop vac, and a couple of sealed work lights. I built mine in my house for under $100(Feel free to PM me for details). This will really help with dust contamination

For removing runs, the harder your sanding block the better. I use a piece of lexan.

The order of sanding/polishing that i use to get a show car shine:
1500 grit wet, with a block.
2500 grit wet, with a block
3000 grit 3M trizact wet, with a DA sander. Wipe with terry cloth
5000 grit 3M trizact wet, with a DA sander. Wipe with terry cloth.
3M white compound on a rotary polisher at low rpm and a foam pad. Wipe with microfiber
3M gray polish on a rotary polisher at medium rpm and a medium foam pad. Wipe with microfiber
3M blue glaze on a rotary polisher at medium rpm and a fine foam pad. Wipe with microfiber.

Each step should take roughly twice as long as the step before.

 

[AlexR]

Re: Help With A Rattle Can Finish?

I would use a razorblade or knife blade to remove most to all of the drip. Sanding is perhaps not the best way as you end up sanding a lot of areas back you don't need to in order to remove the amount of excess.
You can wrap a small amount of masking or sticky tape over the blade ends so the middle is the only area cutting, and you don't go all the way down.
And if its nitro you're using then close enough is ok, as the following layers will melt into what is there already and will eventually vanish during sanding.

 

[Aceman]

Re: Help With A Rattle Can Finish?

Agree with the advice already given. I'm used to working with automotive paints, but the same theories apply to all paint, including rattle cans.

A few other things I would add...
Wear a mask. Paint coats the inside of your lungs exactly the same way it coats your guitar body.

Spray in a warm room. Warmer the better. Paint flows and dries best at 80 degrees f.

Thin coats. I know this was said already but it bears repeating.

FWIW, you can build a cheap downdraft spray booth using 5 sheets of plywood, furnace filters, a shop vac, and a couple of sealed work lights. I built mine in my house for under $100(Feel free to PM me for details). This will really help with dust contamination

For removing runs, the harder your sanding block the better. I use a piece of lexan.

The order of sanding/polishing that i use to get a show car shine:
1500 grit wet, with a block.
2500 grit wet, with a block
3000 grit 3M trizact wet, with a DA sander. Wipe with terry cloth
5000 grit 3M trizact wet, with a DA sander. Wipe with terry cloth.
3M white compound on a rotary polisher at low rpm and a foam pad. Wipe with microfiber
3M gray polish on a rotary polisher at medium rpm and a medium foam pad. Wipe with microfiber
3M blue glaze on a rotary polisher at medium rpm and a fine foam pad. Wipe with microfiber.

Each step should take roughly twice as long as the step before.

Do you have an "abbreviated/faster version of that list above????

 

[MikeRocker]

Re: Help With A Rattle Can Finish?

The order of sanding/polishing that i use to get a show car shine:
1500 grit wet, with a block.
2500 grit wet, with a block
3000 grit 3M trizact wet, with a DA sander. Wipe with terry cloth
5000 grit 3M trizact wet, with a DA sander. Wipe with terry cloth.
3M white compound on a rotary polisher at low rpm and a foam pad. Wipe with microfiber
3M gray polish on a rotary polisher at medium rpm and a medium foam pad. Wipe with microfiber
3M blue glaze on a rotary polisher at medium rpm and a fine foam pad. Wipe with microfiber.

Each step should take roughly twice as long as the step before.

I respect anyone's methodology and whatever works best for them, but for my part I have finished 7 guitars, and I have never used above 2000 grit sandpaper. I don't even know where to readily find anything above 2000. I sanded up to 2000 with each guitar, then used 2 or 3 successively finer buffing compounds and lots of elbow grease. By the end, the finishes were mirror smooth and totally reflective, with no scratch marks.

 

[Taz Rules]

Re: Help With A Rattle Can Finish?

Yeah it's labour intensive and overkill.
It's the method I used on show cars for an absolute glass finish for competitions.

FWIW, the 3000 and 5000 grit aren't strictly necessary, but I find it actually saves time as it reduces the amount of polishing required. Plus a DA sander is far more precise and controllable than any polisher.

The first wet sand, the 1500 grit, is the only stage that does any real smoothing or material removal. Each subsequent stage is only to remove the scratch from the step before. The 3000 and 5000 remove the 2500 scratches far more quickly and easily than polishing does. I can (and have) done the entire process on a black car hood from first wet sand to final glaze in under 2 hours. On a guitar, it usually takes an hour or so. More if I have "positive flow indicators" (aka runs) in the clear. Those I usually hit with a razor blade and 800 to 1000 grit before wetsanding.

There is nothing wrong with skipping the finer grits. Just be aware that it will take more time and effort to polish out the coarser scratch.

 

[Taz Rules]

Re: Help With A Rattle Can Finish?

Do you have an "abbreviated/faster version of that list above????

Yup. Hit it with so damn much clear that the whole thing is one big run. Then just cut the "clearcicles" off the bottom with a very sharp hunting knife.

(I'm kidding, of course!)

 

[MikeRocker]

Re: Help With A Rattle Can Finish?

Taz, I have another project just starting, and I would love to try higher grit sandpaper in order to reduce the buffing (and the arm strain, haha!)...do you have a source you can share for where to get the higher grit papers, ideally where you can purchase a small amount? And thank you in advance!

 

[AlexR]

Re: Help With A Rattle Can Finish?

The micromesh stuff is usually good for the finer grits.

 

[Taz Rules]

Re: Help With A Rattle Can Finish?

Taz, I have another project just starting, and I would love to try higher grit sandpaper in order to reduce the buffing (and the arm strain, haha!)...do you have a source you can share for where to get the higher grit papers, ideally where you can purchase a small amount? And thank you in advance!

Most reputable auto body supply stores will carry it. Bear in mind that 3M trisact is designed to work on a da sander, and will not work well if used by hand.

For small quantities, try asking at a local auto body shop. He may sell you just a couple of pads.

For those who don't know, da refers to dual action sanders. These are pneumatic sanders that have both an orbital and rotational action. They are not cheap. See if you have a friend who has one that you can borrow before buying one. Most hot rodders, or car guys will have one. Definitely any painter or body guy

 

[devastone]

Re: Help With A Rattle Can Finish?

Auto supply stores, some hardware stores, or StewMac.

 

[Artie]

Re: Help With A Rattle Can Finish?

I can't offer any advice, but that chunk 'o wood has the potential to be one sweet looking guitar. Good luck on the project.