Need Painting Advice

[Krazy Hawaiian]

The best thing you can do is check with your local suppliers. Ask when the factory reps are coming down to show how to use there new shit. There almost always free and it will teach you more in a few hours than you would imagine.
I learned from a friend that has been spraying show cars and working for the MB dealer here. He's amazing how he does some things. Won 5 best paint in show awards in the last 8 years or so.
One thing though not just the clear but ALL the new paints today are nasty ass shit. Wear a paper suit (cheap protection) and a air fed respirator (if you can rent a booth chances are there may be a mask you can use, you don't want to be breathin that crap at all..) My friend's lungs look like he's been in a coal mine for 20 years..
He also has pancreatic cancer from that shit. But he's been doing it for almost 40 years and for the longest time never even wore a normal respriator...
Try and go with a solid color if you haven't done much. The metallic/candys are a real bitch to spray. The hard thing is not ending up with dark and light aeras. Getting it even and consistant is way harder than you think. Like Grasshopper said the basecoats look like crap so it can be hard to tell if it's right with some colors.
If you have access to a decent booth or can rent one for a day it will be a huge help (also when taking into condersation you will have a fair amount of $$ in materials it is worth it if you can get a booth) If you got it together and find a clean booth and get lucky you shouldn't need to touch the clear... but that takes a ton of practice..
I always have waterfalls and rivers that need taken out!
John can lay it down so it looks like glass...

[collisionman]

Well I work as a auto body technician and I have a few questions. First are you going to strip the paint right off and start over. and will there be any need to do any repair work on the body before painting. Anyway the way to prep for paint is as follows: 1) to strip all the paint completely off use 80 grit sandpaper this will take the paint off very quickly so be careful. next if there is no repair needed use 180 grit and sand the entire thing. then you can prime the bike. if repair is needed it should be done after you have sanded with the 80 grit this will ensure proper adhesion. after you have the bike in primer allow it to dry for an hour or so then you block the primer smooth with 320 grit or 360 grit I prefer 320 once the whole thing is blocked smooth you are ready to spray sealer wich is pretty much the standard procedure for painting today anyway allow the sealer to dry for 15-20 minutes then you spray your base coat lay the first coat on fairly heavy wait 10 minutes spray the next coat a little less heavy wait 10 min then spray your last coat on . wait 15 min. and spray on a medium heavy coat of clear and you may want to put on as many as 5 coats of clear but at least 3. when that is dry like the next day sand the whole thing with 1500 grit sandpaper and then buff to a shine with medium buffing compound be careful not to burn through the clear. my suggestion is to set the buffer on 2 or 3 and move fairly quickly then switch to a polish pad and polishing compound and repeat the process.

[Grashopr]

Kay, all....I've been workin with the Mod's on setting up a much more 'instructive' how-to on painting bikes. Last weekend we got Gixerking's bike done, but we didn't get many pics taken. As the season goes on, I'll be taking pics and writing up how-to's so hopefully by this winter, you all will be able to strip and re-spray your own bikes with wreckless abandon! Anyways...I'm taking offers now. If anyone would like to see how to do a specific step (you're in the middle of something right now and need to see it soon), request it. Please dont ask for Clearcoat how-to's...I have already begun the pics for that one, and will be working on the sanding/buffing how to this weekend...any others that are high-priority for you guys?

The 'hopper

[sketch]

graphic artist for the bike masses anybody want to know more
about complex graphics for bikes just say it

something a bit hard or higher level then routine stuff i will give all
i know just pm me but i think there are enough people here that can help
with prep work

but i like the different styles or techiques for prep
its good to for even me just to hear someone else take on
that stuff


sketch,
Master airbrush and tattoo artist

[ocbasbalburg]

After you spray on the basecoat, should you sand before you put on the clearcoat? On all the tv shows, after they paint, they wet sand the hell out of the car/bike before they put on the clearcoat. So far, I haven't seen it written that you should wetsand before clearcoat.

[Grashopr]

You should not need to sand your basecoat before clearing. IF you SOMEHOW (this is a BIG if) got a run in your basecoat, you'll need to sand that flat and re-spray your basecoat, but after spraying your base, you should not need to do anything but tack-wrag it, and spray clear.

[ocbasbalburg]

I am doing a rattle can job.... I went ahead and sanded after the basecoat and then clearcoat. So far it turned out good. I am still not complete with all the pieces, but I am pleased with what I did so far. One other question, what do you use to buff? I just used some meguires, but my dad said something about rubbing compound?

[kawagirl]

sheesh that is some awsome advice there graswish I had read it before I started..but the next time I paint I will use your advice thanks

[Grashopr]

Maguires (sp?) makes some really nice POLISHING products, but most of their line is not made for bringing something back up to shine after being color sanded. I personally use the 3M Perfect-It II line, which consists of 3 liquids. You can get the entire system at any O'Reillys that sells paints, or at your local automotive paint supplier. I always mix up what the name of the liquid is that does what, but you need to use the following liquids to make it shine after you've sanded out all of your scratches, up to like 1500 grit: (not necessarily in this order)

Cutting Compound (this takes out the 1500 grit scratches)
Rubbing Compound (this begins to make it shiny, some people stop after this)
Polishing Glaze (either hand glaze, or polishing pad glaze...DONT try to use the polishing pad glaze by hand, it's just not aggressive enough, you'll wear out your muscles for sure. This makes it REALLY shiny)

You can get all of these items plus some other polishing necessities at THIS WEBSITE for about 60% less than you'll pay at O'reillys.

The 'hopper

[P455]

Grashopr and other pros: thanks for the informative posts, LOTS of good info here.

I have a painting question: My 92 GSXR was originally the black/pink/purple model. The previous owner couldn't hang with the girly pink stripes, so he pulled them off, BUT they were under clearcoat. So he used a razor to cut through the clear then pull off the stripes.

This leaves me with a crappy looking bike with sharp, raised clear edges. I've sanded down the side panels to one smooth level, but in doing so, I sanded through the original paint to bare plastic.

I've now got the side plastics very smooth and need to start thinking about putting paint on them. I am going to spray a basic black BC/CC with a gravity HVLP gun. I plan on using PPG Omni products. I have some MP170 epoxy primer and some MP182 2k urethane primer.

My question (finally): do I need to use an adhesion promotor/tie coat on the bare plastic (I have some, made by transtar) or can I just shoot a coat of epoxy primer (sticks to anything, right?) then lay down a couple coats of 2k urethane primer to block sand? If I could skip the adhesion primer step it'd give me less film build and less chance of chipping.

If I do need the transtar, should I then shoot epoxy over that before using the urethane 2k? What are your thoughts on flex additives for bike plastics? Should they be added to all layers, primer, base, clear?

Thanks again for sharing your expertise with us!

Mike

[Grashopr]

Originally Posted by P455

My question (finally): do I need to use an adhesion promotor/tie coat on the bare plastic (I have some, made by transtar) or can I just shoot a coat of epoxy primer (sticks to anything, right?) then lay down a couple coats of 2k urethane primer to block sand? If I could skip the adhesion primer step it'd give me less film build and less chance of chipping.

Adhesion promoter is not necessary if you degrease/prep the parts correctly. Save your money.

Dont worry about the Urethan Primer for block sanding. Use the High-Build Epoxy primer if you've already bought it as your Sealer over the old stuff, as your leveling device (just put enough of it on to block-sand it unless you have really bad areas that require hand-applied putty), and as your final sealer if you DO end up with some catalyzed plastic (putty) in it. Epoxy primer, if used to the specs, is a TERRIFIC tool for painting anything. It will still to anything with a mechanical bite (wont stick to chrome, glass, or super-smooth surfaces) and is a PERFECT surface for basecoat to adhere to if drying times and mixing instructions are followed. Skip the 2k Urethan Primer, as it's pretty much the same as the Epoxy, it's just built for high-build applications and has the ability to be cut with Urethane Reducer. I refer to the 2k as 'polyester' because it's like liquid putty...it goes on SOO THICK!! You can fill 36 grit scratches (and I mean FILL) in 2 passes with that stuff. Yes, it sands nice, but if you're bodywork isn't THAT cut up, you shouldn't need anything but the epoxy primer.

The number of coats doesn't really create a chipping problem until you get to the clearcoat. Yes, if your putty is 3" thick on a surface that has some 'give', you are prone to having problems, but chances are your overall thickness from plastic to polish wont be more than 3/16" thick. When you get a 'chip', it's usually just in the clear. If your chip goes all the way down to the plastic, no painting techniques are going to help avoid whatever boulder hit you from doing the damage that it did. What you are trying to avoid is getting hit by a june bug or small child, and ending up with a big chip. Typically, everything under the clearcoat is so thin, and so flexible, that it doesn't really cause any problems, it's your clearcoat that can give you a headache. Everyone wants that 'super deep' shine, but most people think that requires TONS of clear (it doesn't, but I wont get into that right now). The clear actually hardens to a more-rigid-state than the underlying layers. If your clear is thin, and it gets hit by something, it gives a little bit, but generally stays together. The thicker that your clearcoat is, the more brittle it can become (depending on painting techniques; dropping 3 gallons of clear on something all at once is going to be VERY brittle, putting on 2 or three coats, letting that cure, sand, then more coats over days and days of curing and sanding, respraying will create a very very deep, very strong coat of clear....but that's not for this discussion). So dont worry about how many coats you have right now, chances are the most you'll end up with on the peice is 15 or 20mils of clear, which isn't too much, and it's not too little.

Originally Posted by P455

If I do need the transtar, should I then shoot epoxy over that before using the urethane 2k? What are your thoughts on flex additives for bike plastics? Should they be added to all layers, primer, base, clear?

Mike

IF you feel that you need to epoxy it AND 2k it, NO, you dont need to seal the epoxy before shooting the 2k..just remember, the 2k mainly sticks to things through PHYSICAL bite..so make tripple-sure that you have the Transtar sanded and degreased correctly, then shoot your 2k, block it out and if you want, shoot another coat of hte Trans-star over the top just as a 'super-safe-sealer' coat.

Flex additives are actually a misleading product. They are designed to give a peice some flexibility in the clear for installing. A good example is the front nose-peice on allot of corvettes. That thing has to be twisted into some pretty funny shapes to get it to mount right, and there have been instances where the basecoat or the clearcoat was so hardened that it developed stress cracks when being installed. You are painting this with a BC/CC...think about it...it's URETHANE..what is urethane? PLASTIC!! The urethane basecoat is actually a modified plastic base that is tinted to get the color, and metal flakes/pearls are added for lighting effects. The Clearcoat is an altered Enamel. The only time you will really run into 'rigidity' issues is when you start using Acrylic Urethanes or Acrylic Enamels (single-stage paint). Some manufacturers use different types of catalysts in those that actually cause them to become rock-hard and when the panel behind them moves, they can crack.

Dont worry about the flex additive, use the money to buy fish-eye remover. It's a safer bet.


The 'hopper

[P455]

Thanks for the info! Now if I can just find the time to get this thing prepped and painted!

[apchasse]

I spray rattled mine.....it is all fiberglass except for the tail..

All I did was fix any spots that needed attention, primer, basecoat, then clear.

I can say that I have used expensive paint, and the clearcoat is ten times better. With the rattle can clear, it is really soft, and you DONT want to spill gas on it..I learned the hard way! But this is what it came out like with the rattle can...not to bad for $30 in paint!

[R&D]

One other little peice of info that I didn't see mentioned, maybe just didn't see it but when you are spraying the sealer and base coats, it is a very good Idea to tack off the panels between these steps. There is a ton of overspray laying on the surface that needs to be removed before the next coat of base is applied. This will help keep trash to a minimum and keep the surface nice and smooth. Good paint job will usually not have to be wet sanded and buffed other than just for trash removal. Also, if you have graphics, do yourself a favor and wetsand the clear to remove the edge lines and reapply the Clear. This adds much more depth and leaves a glossier finish than a standard clear coat over Graphics.