jcurrieirocz

Hey guys
im starting my first full car and i want to know what i should do for the bumpers of the firebird....this thing is an 82 and it has a good amount of paint chips on the plastic/urathane bumer cover and i was wondering how should i attack it. The guy im getting to spray the car is getting me to finish the whole car with 320 and then hes ganna use a high build primer and urathane dupont black. Keep in mind all i want is better then a back yard job but nothing exactly perfect.

Is it ok for me to sand the problem areas in the bumper with like a 150 or so then work up to a 320. Im useing a air da sander and a hand block... beacuse the bumper has soo much paint on it id rather not use a block or it would take to long.... i do know that i cant let the plastic get too hot or ill mess it up. any more advise, on the rest of the car????? thanks

TA_drag

I have the same problem. I was afraid to try to sand thru all that thick paint because I think I will start to distort the bumper. I have seen a product called bumper stripper, it says that it will strip paint but not affect the factory baked finish. I dont think I have any finish underneath just looks like yellow urethane ? to me. So I was afraid to try it -I would rather have bumpy nose than melt it off

camaro430sut

iTrader: (2)

i use the bumper stripper at work all the time, i do colision repair. it works real good and will not harm out urethaine bumpers. i have however seen it remove the factry finish, sometimes it does, sometimes it doesnt. the stuff i use is SEM bumper stripper in aerisol cans. itll prolly take you two cand per cover. this is your best bet to remove many old layers. however once the bumper is stripped to bare plastic i would sand it with 220 grit and then hit with three coats of uerithaine primer and block sand (360-500 grit depending on color) after that to a smooth finish, then paint it
matt

Cruzin Kaz

Excellent advice here by this man. Be sure to avoid circular motion for your final sand before paint. I find you always get a much better finish, and reduce the chance of unwanted runs...

TA_drag

Do you add some type of flex agent to the primer and paint so It doesnt crack? I have heard of it but never seen any.

camaro430sut

iTrader: (2)

flex isnt required in the new urethaine paints. these types of parts are flexible enough to be used on plastic bumpers. same thing goes for urethaine primers.
matt

KEVIN G.

Token

I used PPG products, and when I was about to spray my K36 primer, I added their 814 flex agent. Works well. But don't worry about overheating the plastics, they're almost impossible to melt. Just use a DA with 150 grit and then 240, maybe even 320 if you feel its necessary. But using a high fill primer you don't really need to worry about using a high finishing grit. I started with 80 grit, because I found out there were SEVEN layers of paint on my bumper... took them all off.

Modern paint/clear does not require the flex agent. I used Deltron DBC 2000 color and DCU2021 urethane clear. Came out nice.

KEVIN G.

Rabbitt

u about the flex agent thing? I emailed HOK directly and they told me their products do NOT require any type of flex additive.. i can forward u the email if you would like

Z28ricer

iTrader: (2)

I went round and round with him on this same subject a while back, even showed him where directly from HOK it states that their products cure flexible and do not require a flex additive, in addition he also wanted to spout off about PPG and the same subject. Heck i've got a chunk of clear from the leftover after the last paintjob I did with PPG, its about 7/16" thick and is flexible, go figure...

dennisbernal91z

iTrader: (2)

Now that you guys are talking about painting the bumpers, how do you fill in the emblem? A little body filler?

That bumper up there ^^^^^ looks great. Any other tips?

Rabbitt

lmao, i know, it was in one of my threads!

oh well

KEVIN G.

Yes I have "spouted off"
Because I am certified in about four different paint lines and GM certified and ICAR certified... I have been trying to educate everyone on here, (to much abuse frome everyone I try to counsel, I may add.) about The necessity of flex additive.
Everyone wants to know the "correct" way to do something, on this forum, and though I give you the standpoint from an educated and experienced professional...I catch h-e-l-l for it and get all kinds of flack.
Let me come to your work...and tell you you don't know **** after 20 years of doing and being around your chosen field.
I have been sufficiently chastised on this subject and will no longer "spout off" about flex additive.
Know this...If a customer comes to MY SHOP and gets the bumper painted, they will get flex additive in the primer, sealer, and clear.
It is the correct way to refinish a plastic part.

eric17422001

The one product I haven't heard mentioned here is an adhesion promoter- such as 'bullldog' brand. Should that be used on a raw urethane part?

eric17422001

The one product I haven't heard mentioned here is an adhesion promoter- such as 'bullldog' brand. Should that be used on a raw urethane part?

Z28ricer

iTrader: (2)

If I was going to put that much emphasis on my experience with the stuff, i'd at least take the time to fully read the product sheets and not contradict what the manufacturer specifies. The PPG sheets specify time limits on the flexibility which correspond with the same info I posted before about it outgassing from the clear after a certain time period and only being important when spraying a flexible bumper while it is not on the vehicle and having enough time to get it onto the vehicle without damage due to possible extreme flexing.

KEVIN G.

I respond by referring to all my earlier posts: "That is for all "oldschool flex additives...MOST paint companies now produce a TRUE RESIN FLEX that DOES NOT FADE. It IS THERE FOR THE LIFE OF THE CLEAR."

Try educating YOURSELF in something other than one product.
My manufacturer SPECIFIES the use of flex.

Rabbitt

if the company has a flex additive, then use it - it obviously needs it if they make it for it..

just sayin, with HOK, they do NOT make a flex additive because their products do not need it...

Z28ricer

iTrader: (2)

Try educating YOUR self in not looking like a fool, I was referring to PPG products and HOK products, in this post and before you would NOT acknowledge that they are fine without flex additive as the manufacturer states. I made no reference to what YOU use needing it, you only implied that the products i've used need it, when the manufacturers state otherwise.

jimp2001

I dont car whay HOK says. I spent $750 on paint, and didnt add flex because they said I dont need it. A nice size rock hit my nose while crusing down the road, paint cracked like a windsheild!

Man was I pissed!!!

dennisbernal91z

iTrader: (2)

Is there a reason why u can't just uese this flex stuff all over the car???? I am just starting to dip my toes into the paint world and am not done reading my first book on it yet. THX for any insight

Rabbitt

then i guess it wasn't painted correctly?

jcurrieirocz

but also doesnt the urathane bumpers themselves have the crackes in them,,, cause if thats the case i dont care how flexable the paint is its still canna crack along with the bumper isnt it?? But say a new bumper without cracks wouldnt crack the flexable paint......

all i can relate it to is you cant make a 5 star meal out of 20 year old food..so in another words the paint is only as good as the bumper your putting it on.

tph87

all i know about the flex additive is what we were told in auto body college. flex additive is only good for about 24-48 hrs, it then evaporates just like a reducer. it is only for when you paint a plastic or ureathane part and then install it on the car so during installation it doesn't crack.
i am not trying to say anything about anybody, i am just stating what we were told in college. (right or wrong)

KEVIN G.

Thank you JIMP!!!! exactly the point I am trying to get acknowledged.


AMAZING!!!
How in the world can you insist on calling me out??? I have never once said to go against the manufacturer!!! Your two, are in fact saying it is not NECESSARY in their products. They are not saying:"DO NOT USE THESE PRODUCTS THAT WE'VE DEVELOPED FOR THE PROFESSIONAL AUTO REFINISHER" "For the every day backyard painter I suppose that's fine... Not for me, or my car, or MY CUSTOMERS!!!
I also would personally not use their everyday line on something of mine that I wanted to keep nice.
PPG, infact, developed their GLOBAL line to compete with the european high end paints. In that line they have just such an elastomeric "resin" flex...D814, reasearch it.
As a matter of point, all the high end manufacturers use it. Akzo (Sikkens)...Standox (which we use)...Glasurit...Spies Hecker, Nexa Autocolor, Formerly ICI, (Whom PPG bought out, also to compete with the european market.). All paints developed for the european market, who incidentally propelled the base clear performance products that are in such high demand today.
From Sikkens' own TDS sheets:
AUTOCRYL® ELAST-O-ACTIF (OE)
FOR NATIONAL RULE
DESCRIPTION: Car body parts made of deformable plastics require special flexible paints. Additions
of Autocryl Elast-O-Actif improves the flexibility to such an extent that the paint can tolerate deformation of the plastic parts without cracking or chipping.
GLASURIT:
Topcoats or clears must be elastified by adding Glasurit® 522-111 Softface Additive before being applied to plastic materials.
Nexa Autocolor:
All plastic Priming Systems can be directly topcoated with the recommended Nexa Autocolor 2K or AquabaseTM topcoating system**. Over flexible plastics, 2K topcoats
and clearcoats should be modified with Flexible Additive for plastics P100-2020 at the appropriate mixing ratio.
Spies:
- Add 15 - 30% Permasolid® Elastic Additive 9050 to Top Coats and Clear Coats, on all commonly found types of plastics (not necessary on reinforced fiberglass).
- Add 30% Permasolid® Elastic Additive 9050 to 2K Surfacers.

I am sick and tired of punks like you, who have painted two or three cars, that think they know everything there is to know about body and paint work.
I was working in shops when you were in diapers!!! I keep an OPEN mind and learn all I can about my PROFESSION!!! When you shut your mind down to new ideas... you're done!!!

Call me when YOU are running a damn near million-dollar-a-year body shop.
Call me when you have customers that expect the best product available, and expect you to stand behind it.
Call me when some shopping cart slugs your bumper and the paint spiderwebs and shatters.
Call me when you learn something.
I am done arguing this point, You guys are old enough to make an educated, informed decision. I give you the tools and information, do with it what you will.
If anyone is interested in any kind of body and paint question, PM me, cause, although I will offer my advice on the subjects here of which I am knolwledgeable...You will no longer see my posts in an open debate. I do not wish to make enemies, I only wish to help.

jimp2001

I also had a problem painting my car... apparently HOK doesnt like DuPont Paint too much. My old '89 was repainted a few days before I bought it. Porperly stripped to the metal, etc. etc.

I hated the color, so I wetsanded it and left the Dupont Chroma basecoat on the car. When I laid down my new silver base for the candy blue... it alligatored everywhere there was dupont. I had to sand the whole thing down again and prime it before painting.

Just a little note for anyone planning on using the HOK shimrin basecoats.

-Jim

Rabbitt

HOK clearly states not to use their products with ANY other brand

Z28ricer

iTrader: (2)

http://www.ppg.com/refinishftpsite/d...DCU2021pic.pdf

PPG deltron, far from cheapie clear, someone with half a brain please see how hard it is to find out when the flex additive should be used, according to the manufacturer.

Kevin, you need not prove your stupidity any more, you are now contradicting the crap you were spewing the last time this was brought up, badmouthing ppg and their "outdated" flex additive, and HOK not needing a seperate component, completely ignoring the fact that it isnt completely impossible for a chemical company develop a way to just completely incorporate the properties into the same mix, rather than making it an extra component.

casebaseball205

sorry guys. i just got done refinishing my car this weekend. we used the flex. my cousin is a bodyman and a huge dealership and they use it too. he says that you should "always" use it on these kinds of bumpers

Z28ricer

iTrader: (2)

And again, you should always follow what is specific to the manufacturers specs for the products you are using, if the paint you are using states it is only for spraying a part that isnt mounted on the vehicle, guess what, you are probably wasting your time using it on a part thats already mounted.

dennisbernal91z

iTrader: (2)

is it better to paint parts on or off the car?

Z28ricer

iTrader: (2)

For the most part it would be better to have the part on the car since you'll have less probability of hurting the part between spraying it and getting it mounted, and it wont get flexed much that way. Though there are times you may need to paint the part off the car, or it may allow you to do a better job.

dennisbernal91z

iTrader: (2)

Can you classify these "better off the car" parts? My car is 100% taken appart, and I am painting it, so i can go either way.

Seems like it would be super easy to assemble it and paint it that way. Sounds too good to be true kinda easy. I have seen other guys paint all possible things disassembled. I don't need the car to look like a show car, but I have tossed about 20 grand into it, so I would like it to look at least as good as the Stock white paint did. Thanks.

Rabbitt

what about the bumper covers? some people say to paint those separately because the paint may stick in the line and spider the rest of the paint out...

also, off subject, but now that im thinking about it.. my doors seem to sit 'in' from the fender (looking at it from the handle towards the fender).. any way to fix this?

benscool1

Are the ground effects fiberglass or plastic? Do you need to use flex additive when painting them too?

Rabbitt

the rockers, doors, and qp pieces are fiberglass.. the rear bumper and GFX are one piece, and the front spoiler is plastic...
prolly needs flex if the paint manufacturer tells u to.. just give them a call

dennisbernal91z

iTrader: (2)

Any call on the best apint to get if I just want my car to be WHITE. Just look like stock Artic white. Should I go get whatever GM uses? Thanks guys.

Any suggestions on a "better" white? (if there is such a thing)

Z28ricer

iTrader: (2)

Thats correct on the early cars, 91-92's the side gfx and rear 1/4 pieces are also urethane just like the front and rear bumper covers, and front skirt. The door pieces im not exactly sure they seem to be a composite plastic, cause they actually break when the rocker panel would just flex.

As far as parts off the car, theres some stuff that would just allow you to do a better job even for a normal paintjob to have off, like say the 91-92 Z28 spoiler, the mirrors, gas filler door, different things like that depending on how nice of a paintjob you want. Course if you are really going all out, painting everything seperate would let you get away with no paint lines, if the doors were off you could spray the jamb at the same time as the rest of the car, and the inside of the door at the same as the outer, etc.

Z28ricer

iTrader: (2)

I'd suggest PPG's deltron DBU basecoat and DCU2021 clear, or Global BC base and D894 Clear.

dennisbernal91z

iTrader: (2)

i know I need to learn more, but isn't base coat just the stuff you plra on right after the primer? Is that the acctual paint that will cover the entire car car eventually? Just in mnay coats?

Also is there a prefered primer?

i hear stuff about high buildup primer/ "normal" primer/ hard primer, and so on. Is there a "best" way to go? Just want it to look/feel like stock. Thanks again guys. i will finish that paint and body book I have tonight so tomorrow my Qs are not so stupid. hehe.

Rabbitt

you base coat is the actual paint, the color..
primer/base coat/clear coat

dennisbernal91z

iTrader: (2)

Ahh, ok I am thinking straight. Thanks again.

Is painting acctaully hard? in terms of skill.... Should I prcatice on an old door, till I have it down perfect before moving onto mycar? I feel like I can learn quick, but don't want to spend a ton of $ on extra paint...


Oh and how much paint do you guys usually need to paint the entire car...?

sorry for all the Qs but they are all pretty random and don't feel like they constitute their own thread.

Z28ricer

iTrader: (2)

You may also want to consider a sealer, so it would be more like primer/sealer/base/clear. Just depends on the primer, and how nice of a job you want. From my experience PPG and HOK work fine together and HOK's primers / sealers are a lot cheaper than PPG, the same is true for the rest of their stuff too, but it depends on if you want a factory color or something else. As far as how much, depends on how complete of a job you are doing, what brand and color the basecoat is, and the background you are spraying it onto, for instance if you were painting a black car white, you probably wouldnt get full coverage in 2 coats, definetly not with some of the cheaper lines of paint, however if you used a white sealer over the car then you would have the correct background and need less coats for full coverage. This not only helps with needing less paint, but you'll also find that going around the car with a quart of paint or so loaded up in a gun gets kinda tiring, so if you use a cheap paint and have a very different background you'll find yourself going around the car many times, tired, and maybe even not having enough basecoat to get the color correct.

dennisbernal91z

iTrader: (2)

Ok, I see. Thanks for the info Z28. I think I know all that I need to know till I paint.

If there is any other bits of info that you guys can think of please fill me in, I am just going to tell you what I got and what i want.


I have a:
-white car
-pretty good paint
-just about 0 body work needed exept the custom door stuff
(no handles or locks)

I want:
-Fresh coat of STOCK arctick white
-No emblems, anenna, handles or locks
-Nice thick paint, I can spend a lot of time and $ on it. Just don't want to over spend.

Z28 or anyone else, if you can tell me how to get to my goal that would help me out tremendously.

And thanks again, I woldn't be able to build this car THIS way without all the advice I get here.

tom3

Had my car painted with the Dupont Chroma base/clear. Had the front bumper repainted twice now. Any contact and the paint shatters, peel it off like a strips of thin glass. I'm thinking even this paint needs something extra.

Painting in pieces is fine for solid colors, and I like to paint like this when possible, but I guess metallics are better painted on the car all at once to get the flake all oriented the same to avoid color shift. I don't paint metallics, takes an artist, which is why I had a pro do my 88.

The artic white should be pretty easy to paint, white is about the most forgiving color there is and your car sounds like an easy prep. Might look at GM frost white? Really white.

dennisbernal91z

iTrader: (2)

Hmmm. Frost white you say???? What cars come in that color? White is white, but REALLY white might make it look cooler. hehe.

oxiderush

my 90 nose is a little dimpled and warped. Is there anything i can use like a bondo that can flex? never worked w/ plastics before...

KEVIN G.

See my sticky here for detailed plastic repair method...
If they're small enough you can just sand them out of the plastic and prime and block the dimples out.

Rabbitt

not to hijack (just dont want to make another thread on body prep.. dont wanna be pissing people off ) but how do you go about blocking the weird areas? (fender and qp flares and such)