A newbie doing paint and body
06-08-2006, 02:04 PM
#41
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I bought 90% of the stuff on the internet. All the paint, and most of the supplies.
I do have some problems now though.
Last Tuesday (May 30), I stuck the hood on the car. It still looked pretty good. This past Monday (June 5), I was looking closely at the hood, and saw some bubbles in the paint. These bubbles have gradually become more prominent as time has gone on (I assume due to the paint continuing to release solvents and shrinking a little).
The bubbles correspond with my second pass of the basecoat. They are definitely under the base, and they are distributed along those horizontal lines.
I stopped by the paint store today to get some more stuff (going to do a little firewall painting this weekend on my 94Z before sticking the motor back in), and I asked them about it. A guy came out to look at it, and he says it really looks like oil or silicon contamination under the base. From my perspective, there's only a couple places it could come from: improper use of the solvent based wax and grease remover (likely candidate); or dirty hose for my air blower (used to 'dust off' the hood before painting) - the air blower is hooked to the same connection that the paint gun is hooked to, and the hose is brand new, but I've heard of some hoses having slight oiling in them.
I'm leaning towards improper application of the wax and grease remover. I'll be more careful next time.
And even though I'm running a Motorguard .01 micron filter in the air supply, I purchased one of those small gun-mounted bulb filters today. I'll run one of those next time as well.
So while the hood looks good in those pics, it no longer does.
But it's a learning process, and I knew it was a test run.
The metallics came out VERY well though. I'm happy with that. In direct sunlight, looking very very hard, you can see a touch of tiger striping if you look for it, and that's the distance I held the gun from the surface, I'm sure. But any sort of regular looking, down to casual glance, all you see is an even spread of tiny pearls dancing in the light.
I do have some problems now though.
Last Tuesday (May 30), I stuck the hood on the car. It still looked pretty good. This past Monday (June 5), I was looking closely at the hood, and saw some bubbles in the paint. These bubbles have gradually become more prominent as time has gone on (I assume due to the paint continuing to release solvents and shrinking a little).
The bubbles correspond with my second pass of the basecoat. They are definitely under the base, and they are distributed along those horizontal lines.
I stopped by the paint store today to get some more stuff (going to do a little firewall painting this weekend on my 94Z before sticking the motor back in), and I asked them about it. A guy came out to look at it, and he says it really looks like oil or silicon contamination under the base. From my perspective, there's only a couple places it could come from: improper use of the solvent based wax and grease remover (likely candidate); or dirty hose for my air blower (used to 'dust off' the hood before painting) - the air blower is hooked to the same connection that the paint gun is hooked to, and the hose is brand new, but I've heard of some hoses having slight oiling in them.
I'm leaning towards improper application of the wax and grease remover. I'll be more careful next time.
And even though I'm running a Motorguard .01 micron filter in the air supply, I purchased one of those small gun-mounted bulb filters today. I'll run one of those next time as well.
So while the hood looks good in those pics, it no longer does.
But it's a learning process, and I knew it was a test run.The metallics came out VERY well though. I'm happy with that. In direct sunlight, looking very very hard, you can see a touch of tiger striping if you look for it, and that's the distance I held the gun from the surface, I'm sure. But any sort of regular looking, down to casual glance, all you see is an even spread of tiny pearls dancing in the light.
06-08-2006, 02:07 PM
#42
By Metallic are we talking about low riders and their candy apple red with metal flakes? Or are you even saying that a stock Pewter (which I assume is a mettalic) is hard to paint?
I just received my LS1 style fender yesterday and it made me think: Painting along the side of a camaro, paints across three different surfaces:
Front Fender (PLastic)
Door (FIberglass)
Rear Quarter (metal)
Do each of these sections require different prep and/or spray techniques?
I just received my LS1 style fender yesterday and it made me think: Painting along the side of a camaro, paints across three different surfaces:
Front Fender (PLastic)
Door (FIberglass)
Rear Quarter (metal)
Do each of these sections require different prep and/or spray techniques?
06-08-2006, 02:40 PM
#43
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I'm talking metallics as found in standard colors; IE Navy Blue Metallic, Pewter (which is a metallic), etc... you'll see bits of metal flakes in there.
Keep in mind my ramblings here come from "books", and not from experience...
Metallics depend on the gun to break apart the paint and evenly distribute the particles along the surface. And then, gravity takes over and helps to orient the metallic particles, and they set up when the solvent flashes off. The distance from the gun tip to the surface, air pressure, reducer content, humidity, temperature, speed of reducer - all impact how 'dark' or 'light' the metallic paint looks when the particles lay down. That's why "they say" that you shouldn't paint metallic jobs by panel, because you'll end up with panels being different shades, even though they come from the same can of paint. The particles lay down differently.
And that's why a good gun is critical when spraying metallics... gotta break up the paint so it hits the surface properly. Otherwise you can have mottling / splotching, or tiger striping. If I'd held the gun a couple inches further from the surface, I probably could have had zero tiger striping with my GFG-670 gun.
With metallics, you also need to paint the panels in proper orientation... hood laying flat, fenders standing vertically, etc - to get the right 'look' on the tiny metal flakes as they lay down.
As for plastic, SMC (not fiberglass, but SMC) and metal, honestly, it looks to be all pretty similar. Clean it good first, scuff it if it's got well adhering paint on it, prime it, paint it, clear it. If there's bodywork (like on the metal part, in my case on my Camaros), I'll use a high build primer. But for my front fenders, which are currently in perfect shape except for swirls, I'll just clean, scuff, and shoot.
Keep in mind my ramblings here come from "books", and not from experience...
Metallics depend on the gun to break apart the paint and evenly distribute the particles along the surface. And then, gravity takes over and helps to orient the metallic particles, and they set up when the solvent flashes off. The distance from the gun tip to the surface, air pressure, reducer content, humidity, temperature, speed of reducer - all impact how 'dark' or 'light' the metallic paint looks when the particles lay down. That's why "they say" that you shouldn't paint metallic jobs by panel, because you'll end up with panels being different shades, even though they come from the same can of paint. The particles lay down differently.
And that's why a good gun is critical when spraying metallics... gotta break up the paint so it hits the surface properly. Otherwise you can have mottling / splotching, or tiger striping. If I'd held the gun a couple inches further from the surface, I probably could have had zero tiger striping with my GFG-670 gun.
With metallics, you also need to paint the panels in proper orientation... hood laying flat, fenders standing vertically, etc - to get the right 'look' on the tiny metal flakes as they lay down.
As for plastic, SMC (not fiberglass, but SMC) and metal, honestly, it looks to be all pretty similar. Clean it good first, scuff it if it's got well adhering paint on it, prime it, paint it, clear it. If there's bodywork (like on the metal part, in my case on my Camaros), I'll use a high build primer. But for my front fenders, which are currently in perfect shape except for swirls, I'll just clean, scuff, and shoot.
06-08-2006, 05:04 PM
#44
Nice choice of color... I've sprayed a bit of that too, the metallic is very touchy to base/primer color and panel orientation like you said.
Sounds like you've done a lot of research. I've done a fair amount of 'home' bodywork in the past including painting my old '83 short bed p/u. But that was a solid color base/clear, not metallic. One thing I learned from that project was to use a chemical stripper as much as possible to remove old paint. DA'ing takes forever and left a bunch of sanding scratches in the metal that I didn't notice until after I was done. The paint was perfect on the new panels that I didn't have to DA a bunch of old paint off.
Another thing, painting horizontal panels (hood, top, etc) is WAYYYY easier that vertical surfaces (fender, doors). The clear is a lot harder to judge between wet enough and too wet and its easy to get sags/runs. I'd imagine spraying metallics will be similarly difficult on vertical surfaces.
Last, keep in mind even an average finish can still be made to look damn good with enough wet sanding/buffing afterwords. Thats a whole other art to itself though.
I've sprayed a bit of that too, the metallic is very touchy to base/primer color and panel orientation like you said. Sounds like you've done a lot of research. I've done a fair amount of 'home' bodywork in the past including painting my old '83 short bed p/u. But that was a solid color base/clear, not metallic. One thing I learned from that project was to use a chemical stripper as much as possible to remove old paint. DA'ing takes forever and left a bunch of sanding scratches in the metal that I didn't notice until after I was done. The paint was perfect on the new panels that I didn't have to DA a bunch of old paint off.
Another thing, painting horizontal panels (hood, top, etc) is WAYYYY easier that vertical surfaces (fender, doors). The clear is a lot harder to judge between wet enough and too wet and its easy to get sags/runs. I'd imagine spraying metallics will be similarly difficult on vertical surfaces.
Last, keep in mind even an average finish can still be made to look damn good with enough wet sanding/buffing afterwords. Thats a whole other art to itself though.
06-19-2006, 05:47 PM
#45
So, once again, if changing colors. would you remove teh rear hatch and weather strip and paint all teh jams? remove the door and paint the jams and inner door? What about fenders and bumpers (where the seams meet) do you paint all of this area too? Then when all is dry, assemble and paint the exterior sides?
06-19-2006, 09:57 PM
#46
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Yessir, that's my plan.
I picked up a Harbor Freight mini-HVLP gun (This one). I used it this weekend to paint the inner front wheel wells on my 94Z... I removed the subframe doing the engine swap / front suspension upgrade, so the area was open... there were a few scratches, a little surface rust... so I thought I'd paint it nice...
I turned down the air pressure to like 5-10 psi at the gun, and the thing sprayed with virtually no overspray. I didn't even have to tape off areas. The end result had a little orange peel, but it doesn't look bad at all. I intend to take the same approach when cutting in those jambs. Use the mini-gun, and cut in the jambs. For the 'all over', I'll use the big gun. The mini gun uses far less paint than the big gun.
I picked up a Harbor Freight mini-HVLP gun (This one). I used it this weekend to paint the inner front wheel wells on my 94Z... I removed the subframe doing the engine swap / front suspension upgrade, so the area was open... there were a few scratches, a little surface rust... so I thought I'd paint it nice...
I turned down the air pressure to like 5-10 psi at the gun, and the thing sprayed with virtually no overspray. I didn't even have to tape off areas. The end result had a little orange peel, but it doesn't look bad at all. I intend to take the same approach when cutting in those jambs. Use the mini-gun, and cut in the jambs. For the 'all over', I'll use the big gun. The mini gun uses far less paint than the big gun.
06-20-2006, 12:25 AM
#48
Originally Posted by Camaroholic
Yessir, that's my plan.
I picked up a Harbor Freight mini-HVLP gun (This one). I used it this weekend to paint the inner front wheel wells on my 94Z... I removed the subframe doing the engine swap / front suspension upgrade, so the area was open... there were a few scratches, a little surface rust... so I thought I'd paint it nice...
I turned down the air pressure to like 5-10 psi at the gun, and the thing sprayed with virtually no overspray. I didn't even have to tape off areas. The end result had a little orange peel, but it doesn't look bad at all. I intend to take the same approach when cutting in those jambs. Use the mini-gun, and cut in the jambs. For the 'all over', I'll use the big gun. The mini gun uses far less paint than the big gun.
I picked up a Harbor Freight mini-HVLP gun (This one). I used it this weekend to paint the inner front wheel wells on my 94Z... I removed the subframe doing the engine swap / front suspension upgrade, so the area was open... there were a few scratches, a little surface rust... so I thought I'd paint it nice...
I turned down the air pressure to like 5-10 psi at the gun, and the thing sprayed with virtually no overspray. I didn't even have to tape off areas. The end result had a little orange peel, but it doesn't look bad at all. I intend to take the same approach when cutting in those jambs. Use the mini-gun, and cut in the jambs. For the 'all over', I'll use the big gun. The mini gun uses far less paint than the big gun.
So you didn't looen or remove teh fenders? I heard that some peoplewill leave them mounted but with gaps between the pieces then bring the pieces together after they've been painted & dried.
I take it when color changing, items like the rear spoiler should be removed to get at the areas between the spoiler and hatch back?
06-20-2006, 08:30 AM
#49
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Originally Posted by Gun5
damn I was reading this and looked.. u live in waco texas to.. i might need a front bumper for my white firebird repainted u mind helping a rookie?? 
But yeah, we could probably work something out. I am going to be building a small booth soon, I'll probably make another thread for that. It's going to be used for painting panels off of the car. My availability is very sporadic, and right now I'm busy with my own projects (like trying to get the 383 in my 94Z - it's ready, just need time to slide the cradle up under the car and drop the car down on it).Now, as far as what I did... All I was painting this weekend was the inner frame rails / strut wells, inside the wheels. I did remove the plastic wheel well liner, but didn't remove the fenders, because I wasn't spraying near or on the fenders.
Let's talk color change. I'm changing colors on the Fiero. It's built just like an F-body... removable panels. I'm going to remove the nose, front fenders, rear bumperskirt, and deck lid. I don't think I'm going to remove the doors, because (1) doors are a PITA to align, and (2) the wiring is a PITA to remove/install for the power locks and windows.
My plan is, once I get the panels off, to first cut in the door jambs - mask off the interior, leave the doors open - and cut in the jambs with the mini-gun, since it can give you a dot about 2" diameter (that's good for control - my GFG-670 is great at about an 8" wide fan, but I haven't had it give me a good small spot). Then cut in the deck lid jambs and hood jambs, and the intersections of panels (like where the rear skirt meets the rear quarter - there's a sunken area there that you can't get paint on unless you have the rear skirt removed).
With my paint (SPI), I'd kick the base with clearcoat activator in these jamb areas. This will make the basecoat harder than without. I'd clear the door jambs, but probably not clear the areas where panels intersect.
I haven't decided if I want to put all the panels back on the car before painting, or if I want to paint them off the car at the same time. With them off the car, you run the risk of scratches during reassembly. And as I learned with the hood, the paint was still fairly soft 24-48 hours after painting... so I wouldn't try to do it then. The hood that I painted is cured now; I think it took about a week for it to reach full cure. I would not try to reassemble the car with 'soft' paint... too delicate.
06-24-2006, 11:16 PM
#50
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Im lazy on a colorchange i buy a gallon of base and a quart of the same color in single stage, shoot all the inner **** in single stage,put it tigether and shoot the outside.
06-25-2006, 12:09 AM
#51
Great thread. I hate paint and body but mabey thats B/C I am always dealing with rust. Had painted my car 4 years ago and did most of the work (everything except the base and clear on the top black half) in my garage and all I did was sweep the floor and open the doors. It came out really well except one spot where a bug landed/died in it but that was in the bed which I was planning on having spray in bedlinered anyway.
If you are thinking of building a paint booth you might want to look into using a furnace blower for a fan, esp the ones with external belt driven motors. They move lots of air and the motor is not in the airstream. There are still some VOC chemicals used in painting. The chances of actually starting a fire with the motor in the airstream are very slim but if you can use fans with motors out of the airstream all the better.
If you are thinking of building a paint booth you might want to look into using a furnace blower for a fan, esp the ones with external belt driven motors. They move lots of air and the motor is not in the airstream. There are still some VOC chemicals used in painting. The chances of actually starting a fire with the motor in the airstream are very slim but if you can use fans with motors out of the airstream all the better.
06-27-2006, 05:02 PM
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good thread man. first 500 is a smidgen rough. it really depends on your paint but i agree with whoever said 1000 for peace of mind. try wet sanding the spots where the bubbles with 1500 grit then a 3 stage polish
06-27-2006, 06:18 PM
#53
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Unfortunately the bubbles are under the base. Somehow, I contaminated on top of the primer coat. Possibly not using the wax & grease remover properly. I did wipe it down with W&G remover before painting, because as I moved the hood around, I did manage to get a little fingerprint oil on the hood. But there are a LOT of bubbles that go in horizontal lines that go across the hood. Kinda weird. Oh well. That's why I called it a Practice Hood going in.
07-01-2006, 05:54 PM
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Originally Posted by Camaroholic
Unfortunately the bubbles are under the base. Somehow, I contaminated on top of the primer coat. Possibly not using the wax & grease remover properly. I did wipe it down with W&G remover before painting, because as I moved the hood around, I did manage to get a little fingerprint oil on the hood. But there are a LOT of bubbles that go in horizontal lines that go across the hood. Kinda weird. Oh well. That's why I called it a Practice Hood going in.
