DGW

I've heard rumours that Bondo brand will shrink back slightly over time, but have never seen this myself. But I have heard very high praises of the 3M brand of boddy puty and glazes.

For gouges and minor dings, Bondo works just fine.

I wouldn't suggest using it to fill cavities or anything.

If you have major fills and/or repairs, I would recommend Marine Epoxy.

It's an adhesive as well as a filler.

It can be sanded, filed, drilled, etc ... and it won't shrink.

Hi,

I'm having a body shop repaint an old sunburst Ibanez body in surf green. The body is actually in very good shape, but there are a few small dents I should probably fill before dropping it off. After reading old posts, I've decided to leave the old finish and just have them paint right over the old clear coat. But I'm assuming I should still sand the old clear and was wondering what grit to use. Also, I'm wondering what type of product I should use to fill the small imperfections with. I have some wood filler, but I'm wondering if I need to sand down to raw wood before applying the filler. It seems like if there's old paint+clear in the gash, the filler might not bind well.

So to recap my questions:

1) What grit wet/dry for sanding the old clear?

2) How to fill/repair imperfections in the old finish before repainting?

Advice?

Thanks much,

Bert

Good body prep is going to determine the final results of your paintjob.

If you found a body shop willing to paint your guitar, consider yourself lucky but don't assume they will do any of the prep work. You have to do this yourself.

Having said that ... a body shop isn't likely to seal the body so leaving the original finish may not be a bad idea.

Hard to say waht grit you should start with without at least seeing pics, but I would work your way up to around 400 just to leave some "tooth" for the paint to stick.

Using a finer grit is likely to cause the paint to chip and flake.

Dents on unfinished wood can sometimes be steamed out, but considering the fact that you're leaving the existing finish, I would maybe use epoxy or even Bondo. Wood filler should be applied to wood, not a finish.

Good luck.

Does anyone know what this stuff is?

Link to RustOleum Lacquer

The companies in the US will not send the tinted lacqers to Canada. I was in the Local Home Depot today and noticed this stuff while browsing. It comes in red, white and black. Is it really a lacquer, suitable for a guitar?

More suitable for lawn furniture IMO.

anyone have any tips on how to get rid of this?

Uh .... paint?

Solvent pop ...

I know this problem all too well.

It's usually caused by spraying too heavy, not waiting the proper flash times in between coats, or using the wrong temp reducer.

In my case, a 1.4 nozzle was the culprit.

I switched to a 1.0 and haven't had a problem since.

Here are some pics ...

And here's a refin I did using the buffer.

Sure beats the hell outta doing it by hand.

I've got the StewMac piece that goes in your drill press ...

The difference between this and the one you made is that the StewMac piece pivots.

I personally find this to be a big advantage.

I'm in the long-term planning stage of a project I'll be working on in the Spring. I want to do an Avenger body and do multiple layers of binding. As you know, there are some serious curves on the trebel horn. I'm considering using maple for the binding. The question is how easy does it bend? If it's not very flexable, how do you bend it? Is any special tool needed to heat & bend it?

I'm guessing a heat gun.

Just a guess though.

DGW.

A pic or two would be great. Thanks for the offer. I have a 1/2 hp motor and a three step pully for adjusting the speed. I just ordered two 3/4 inch pillow blocks. I can pick up 3/4 rod locally. I was just going to put a couple of blocks under the pillow blocks to raise the height a bit and provide clearance for the pully. The motor already has a small pully, all I need is a larger one for the shaft.

I am looking at ordering 6 - 8" buffs, and fine and extra fine compound.

I will level with wet sandpaper to 800, then buff with the fine and extra fine. Should do it up nicely.

I've been using rubbing compound by hand. It's much to labor intensive. I think I spent about 3 hours rubbing out the finish last time, after 1000 grit and I'm still not happy with it. I'm not a perfectionist, but it's just too much work that way.

-J

I'll try to get some pics up tonight J~.

I used to do it all by hand too ... what I PITA!

jmrentis,

Good tip on the padded flooring!

I've never lost grip of a body yet (knock on wood), but ya never know.

Thank you. What size pully do you have on the axel and the motor?

-John

I have the StewMac buffing arbor ...

It's been awhile since I set it all up, but I believe I used the largest of the three pulleys on the axle and a 2" pulley at the motor.

That would mean it runs fairly fast - about 2x the speed of the motor if I'm thinking about this right.

Anyone deal with http://www.caswellplating.com ?

I'm thinking about getting the buffs there, reasonable price and they seem to know what they are talking about.

Thanks again.

-John

Ah, you're right ... I'm sorry.

I used the smallest pulley on the axle, and 1/3hp motor, 1725rpm, and a 2" motor pulley.

I use a "universal" floor stand and built a platform to mount the arbor and the motor assembly.

I also used an adjustable "power twist" V-belt.

Those things are great!

I can snap a few pics if you like.

Thank you. What size pully do you have on the axel and the motor?

-John

I have the StewMac buffing arbor ...

It's been awhile since I set it all up, but I believe I used the largest of the three pulleys on the axle and a 2" pulley at the motor.

I'm putting together a buffer. What height works best? I can put them low, and work the guitars over the top, or chest height and work them vertically. Any preference on what is most comfortable? I will have plenty of clearance from the motor, that's not a concern. I'm planning on double 10 or 12 inch buffs on each side. 2 1/2 ft axel with pillow blocks on a 1 ft wide base.

Oh, and what speed? I can reduce or increase the speed, any suggestions?

I picked up a nice motor with pully and a 3 step pully and some pillow blocks. All I need to do is fine a reasonable source for the buffs. I have a grinder stand to mount it all onto, but it seems very low. I was thinking chest height, but I've not used one before so thought I'd ask.

Thanks!

-John

You never want to work the guitars over the buffer.

Work from the lower end to help avoid the wheel from throwing your body (or whatever) to the other side of the room.

I mount my buffer so the wheel is slightly above waist high.

For me, this height allows me to have the best control and is most comfortable.

Solvent pop.

Kleen Strip makes chemical stripper for various types of finishes (paint, urethane, epoxy, etc..).

Read the lable and make sure you bought the right stuff for whatever type of finish your working with.

Got pics?

The Les Paul bolt-on replicas typically use a neckplate with 4-screws.

However, you could use ferruls if you like and create a 5 or 6 bolt pattern.

Ferruls work great for contoured heels where you can't use a standard plate.

Jim,

Your suggestion with using a 1.0 nozzel worked like a champ!

I immediately noticed better flow and the smaller nozzel allowed me alot more control.

I first shot a couple dust coats, then I did about 6 more light coats in 15 minute intervals.

The finish has a little orange peel, but I can knock that off with a little wet sanding before buffing it out.

Before, the solvent pop wasn't noticable until I would wetsand.

They weren't bubbles trapped in the clear.

They were tiny crator that had surfaced.

Then when I would wetsand, the residue would get trapped in these crators causing tiny white dots.

I eventually learned how to spot these tiny crators before wetsanding.

I can tell this time around (before wetsanding) ... no tiny crators, no solvent pop ... SUCCESS!

Thank you so much for sharing your experience and knowledge.

I run about the same on my compressor and gun. I also use a Iwata LPH400 for clear but it is overkill on something like a guitar ora bike frame.

DGW - I think that a 1.4 tip may be your issue. You would need to move pretty quick to not build a really thick coat. I use a 1.0 in my Sata Mini Jet and this allow me to slow down which really helps in the tight areas that get overlap. I am guessing that you see the most pop in areas that get overlapped while clearing and the flatter areas that get sprayed thinner are better.

Ther are a few ways to spra thinner coats - Thinner clear or move faster or both . Adjusting the gun to each method is important but I would not usually go down on air pressure to spray a thick clear thinner. once you get the gun spraying correctly leave it and learnhow to spray with it. I have used the same settings on my gun for about 4 years and it always works. I would suggest that you start doing some practive spraying and get as much gun time as possible.

Just read through this thread so coming into this late in the day, but I think DGW maybe has your solution here. I suffered the same problems that you're having now when I first started shooting lacquers and I completely understand your frustration. Like yourself I went through EVERYTHING to try and get rid of the problem and was actually becoming completely paranoid about shooting lacquer coats at all.

Not going to go over everything that's already been said here, but I always use a 1mm nozzle for shooting laqcuers on guitars, at 50psi pressure from the (second) moisture trap in my booth and adjusted further on the gun itself as I spray. I shoot one very, very, light dust coat of lacquer to mist the surface of the guitar, leave it for two or three minutes, then shoot a slightly heavier, but still very light coat over the guitar again. This is then left for roughly ten minutes and then shoot another slightly heavier coat (I have shot up to five light lacquer coats with a ten to twenty minute stand between each coat this way with great results). With the Octoral lacquers I use I've never had a problem, in fact I've never had a problem with various brands of lacquer I used over the years using this method. I don't use any solvent to thin the lacquer, just shoot it as it's mixed and it works perfectly. Just ensure you never have your lacquer 'swimming' on the surface and use the minimal pressure at the gun you can to get the necessary atomisation (too much pressure is not good). I tried umpteen different methods of applying lacquer prior to this one, with different mixes of solvents at different pressures, different temperatures and different nozzle sizes, but this is the one that worked for me.

Hope this is some use to you.

Glad you chimed in Foggy.

I've been pretty busy lately and haven't had a chance to try anything out, but I wanted to tomorrow.

I have a decent Devilbiss touchup gun with a 1.0 nozzel ... is this cool to use?

Should I reduce the psi at my compressor from 80 to 50?

And try to reduce the psi at my gun as well (currently 20psi)?

And what type of fan spread do you look for and how far away to you hold the gun from the body? (bare in mind I'll be using a smaller touchup gun)

I've gpt a body ready for clear but I'm really, really paranoid about shooting the clear.

I've ruined so many really nice paintjobs and wasted so much time ... I really hope this works.

Thanks guys.

The regulator and "cheater valve" look very similar, but I think I have the cheater valve.

Sounds like maybe buying a proper regulator and finding a smaller nozzel may be worth trying.

Thanks!

I just switched from an Iwata LPH-80 for my clear gun to a Sata 3000rp.

I run about 80 at the compressor, and reduce it with a regulator in the booth. The Sata I start around 29 psi and adjust from there the Iwata around 20.

Make sure you are using a regulator to control your air presure not an air adjusting valve or a cheater valve on the gun. Regulators keep presure constant, cheater valves or air adjusting valves work by percentage so as available air goes down your air to the gun goes down and you loose atomization.

I doubt this is causing your problems DGW, but want to make sure anyone reading this gets the info. I didn't know any of this until I took some tech training and it blew my mind.

I'm running 80psi at the compressor and adjust down to 20psi at the gun, so that's good to hear.

I'm glad you mentioned the regulator because one thing I've noticed is that the clear tends to "spit" when I try to shoot light coats.

I've tried all sorts of adjustments at the gun (Devilbiss w/ 1.4 nozzel)) and nothing works ... I either get dry dust (too much air) or it "spits". This is why I asked the question about psi and is also the reason I asked about thinning out the clear by adding more reducer. But now that you mention the regulator, I'm thinking maybe I should try this. I'm pretty sure what I'm using now is just a cheater valve.

Any suggestions as to what type/brand regulator I should be looking at?

Do you think this will help?

I would say this is solvent pop and has nothing to do with contaminants. Basically as said before the surface is drying before the clear below can gas out and it causes small bubbles. This can be a issue of the coat thickness or not letting the previous coat flash long enough before recoating. I live in New Orleans and it is hot and humind and I lay it on thick and very rarely see any pop. I like to use the Dupont Chroma clear 7900 which is a 3/1 mix. You do not use any reducer with this clear so the chance for pop is greatly reduced. It can also be reduced some with blender but then you have to spray much thinner and increase the flash times between coats. On the bicycle frames that I paint I use 2 wet coats and flow it like glass and pop has never been a issue. The great thing with the 7900 is the high build with a few coats.

this is a example of my clear with the 7900, 2 coats and no polishing. this is a professional photo shoot from kgsbikes.com . All of the lettering and color is painted also!

I've used Chroma Clear and yes ... I get solvent pop.

I follow instruction sheets to a T, so there's no chance of not allowing coats to flash long enough.

I don't mean to sound unappreciative, but I've heard all of this before and have already tried everything mentioned here in this thread ... THAT"S what makes this so frustrating.

Just curious ... what psi's are you guys running at the compressor vs. the gun?

Like someone said, thin out your urethane and / or shoot thinner coats.

Understood ... how much additional reducer to you suggest?

And if I'm shooting light coats, should I also reduce the flash time? Or does it even matter?

Thanks.

By "climate controlled" I mean temperature, but I also run a dehumidifier and pay special attention to outside conditions as well.

What's the best way to thin out the clearcoat?

I've always followed the manufactures instructions ... 4:1 ratio I believe?

If I add more reducer, wouldn't I just be adding more solvent?

Yes but it's slower to flach so the solvent has more time to escape.

Also there are different temperature reducers in some systems that slow or accelerate flashing.

Yeah, I'm well aware of the temperature rating on reducers ... I use the slowest possible reducer.

So you're saying to increase the amount of reducer and this will slow the curing process and allow it to flow nicer?

How much more do you suggest? 4:2 ratio maybe?

Thanks for the help.

By "climate controlled" I mean temperature, but I also run a dehumidifier and pay special attention to outside conditions as well.

What's the best way to thin out the clearcoat?

I've always followed the manufactures instructions ... 4:1 ratio I believe?

If I add more reducer, wouldn't I just be adding more solvent?

syxxstring - I always make sure all the products I use are compatable.

erikbojerik - Really tiny crators ... so tiny that they only show up after I wetsand.

I have discussed this with my local paint distributor and they have pretty much told me the same thing.

So like I said ... I've tried everything.

That's why I'm now looking into shooting nitro.

I've tried different airflow adjustments, different techniques, different products, ... EVERYTHNG I could possibly think of.

I was sorta hoping you guys would tell me it was a contamenent and that I needed a particular trap or filter, but ... I dunno.

Sealer, primer, basecoats always go on smooth with absolutely no problems, but clearcoat is a bitch!

It's to the point now that I've stopped painting altogether.

I was just hoping you guys may be able to give me some insight.

As you can probably tell from everything I've already tried, this has been going on for some time now and it really sucks.