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-   -   primer wrinkling and i have a huge mess (http://www.hotrodders.com/forum/primer-wrinkling-i-have-huge-mess-159245.html)

glhx 05-29-2009 02:15 AM

primer wrinkling and i have a huge mess
 
I am painting a motorcycle fairing made of abs plastic. I dont know some of the steps i need to take to do this right so ive been at it a while. I started with a dime size dent in the back of the plastic. I now have a mess

i filled the dent with glazing putty (verrry shallow dent) and then continued to knock it down until i thought it was smooth. In sanding this i ate through some of the plastic down to the molding lines. this was not hard to do.....i was using 600 grit. plastic is definitely not as tough as metal. I just sanded the plastic and glazing putty down with 80 to get the new glazing putty to bond to the old. 80 grit eats plastic bad and i should have used 220....but i thought that new putty over old with 220 scratches wouldnt hold. I still dont know which is right.....im really new at all this..

I did some research and found out that bondo absorbs water and solvents. So I didnt know what to do. i sanded it and now i had to clean the dust off so it was clean. so i didnt know what to clean it with. I used wax and grease remover.....i still dont know if this was right.....i also cleaned it with water at some times because my sand paper kept loading up i decided to wet sand....and dont know if i was supposed to because bondo absorbs water

So now i have filler in there and filler on top of that and such. I sanded with 80 grit and then used wax remover and waited a while for it to dry out. Then put more filler on there because i didnt know how to sand it correctly, and what happened......the filler wrinkles on the outer edges in 2 spots.....i still dont know why. I sanded the wrinkled spot out and then thought........i will just put lots of spray can high build on it just to see what happens.....I used wax and grease remover to get the sanding
dust off and waited a while for it to evaporate. I then put on the high build in 3 coats.....i let it flash some between coats......the spot where i sanded the wrinkle off wrinkled again in both spots. Now i have uneven filler and have to put on more filler because i had to get the wrinkle out. with spray can primer over it and its wrinkled in two spots...
i have questions.... i put filler over plastic and used spray primer because im not good with bondo. spray can is cheap so i can learn.....with this primer...do i have to use plastic adhesive promoter on there.....if so then its too late and i will need to start over. i also used spray can because as im not good with bondo as i said.... i cant just put good high build on there and do body work over that like you can with epoxy because it will shrink. I must have redone the filler 5 times. i have 30 + hours in this piece and have picked up some knowledge but i have far to go.....

how in the heck do you clean bondo.
plastic promoter?
why did primer wrinkle?
what grit paper to sand bondo in order to get more bondo to stick?

this is a mess what should i do...i dont know what im doing....except trying to learn how to paint plastic parts........ :confused:

67Mustang Al. 05-29-2009 07:20 AM

Dont give up
 
You will beat it eventually. I am still learning also. I have sprayed several bikes and just finished a set for a 76 Z900 Kawasaki in diamond green. I have sprayed for a long time and still learning .You have contaminated the under surface somehow. I read on this site that if you spray on wax and grease remover out of a spray bottle and use a new rag ( to eliminate contaminants) and wipe off two or three times you should be able to use a highbuild primer/putty out of a putty gun (if you have a compressor and gun) to cover the abs. I normally wet the rag with wax and grease remover and wipe on with the rag. Try both ways.Pressure paks have lots of thinners to squirt through the tiny hole in the nozzle. Do you have a compressor and gun. When i spray over tank stripes with clear i always use a "dry spray" and gradually get wetter as the next coats are applied. If i used a coat with too much thinners the stickers would also wrinkle.
You need to create a barrier over the abs that is not too wet to allow your base coat a chance to cover without a reaction.
keep trying
Cheers
Al.

egroothand 04-27-2012 08:39 AM

Primer wrinkling
 
I have the same issue. I ended up sanding with 400 then 600 down to bare plastic on the wifes Burgman. wiped with Wax & Grease remover then sprayed adhesion promoter let dry then added SEM Flexible primer surfacer and all around the edges where the paint meets the plastic feathered edge I get wrinkles. Very odd

Stick895 04-27-2012 09:42 AM

Instaed of filler you can disolve some ABS scrap in acetone and make kind of an ABS sludge to fill with. More sanding but no adhesion/absorbtion problems. Need to sand through the paint layer or it won't hold but that doesn't sound like your problem at this point.

swvalcon 04-27-2012 10:07 AM

What happening is anywhere you've sanded though the factory paint on your plastic the solvents are getting under the edge and reacting with paint lifting it off the plastic. You have to either strip all the old paint and start new or put down a good coat of a water base primer. Then let that dry good, prep and paint.

MARTINSR 04-27-2012 10:39 AM

Quote:

Originally Posted by swvalcon
What happening is anywhere you've sanded though the factory paint on your plastic the solvents are getting under the edge and reacting with paint lifting it off the plastic. You have to either strip all the old paint and start new or put down a good coat of a water base primer. Then let that dry good, prep and paint.

:thumbup: And there lies the answer. It is also very possible these plastic parts have a waterborne primer from the factory as Saturn plastic part do, and they WILL lift if you sand thru them.

Years ago before we were FORCED (oh how we hate being forced to do things :evil: ) to use waterborne primer here in California we were THRILLED to use it on problem cars. Be it painted with cheap enamel or lacquer over poorly sanded enamel when you painted over them where there was a sand thru it would wrinkle like a madman. There was a waterborne primer called "Barrier coat" or something like that, "Wrinkle free" some name referring to burying some sensitive substrate. I remember in the lacquer days spraying over something that would wrinkle so bad you could almost HEAR it. :pain: Lacquer thinner is VERY aggressive and it would ATTACK soft substrates and wrinkle. A couple of coats of water borne primer and you could BURY it in lacquer sprayed wet with no problem, it was like magic.

Brian

egroothand 04-27-2012 11:38 AM

Additional question
 
Quote:

Originally Posted by MARTINSR
:thumbup: And there lies the answer. It is also very possible these plastic parts have a waterborne primer from the factory as Saturn plastic part do, and they WILL lift if you sand thru them.

Years ago before we were FORCED (oh how we hate being forced to do things :evil: ) to use waterborne primer here in California we were THRILLED to use it on problem cars. Be it painted with cheap enamel or lacquer over poorly sanded enamel when you painted over them where there was a sand thru it would wrinkle like a madman. There was a waterborne primer called "Barrier coat" or something like that, "Wrinkle free" some name referring to burying some sensitive substrate. I remember in the lacquer days spraying over something that would wrinkle so bad you could almost HEAR it. :pain: Lacquer thinner is VERY aggressive and it would ATTACK soft substrates and wrinkle. A couple of coats of water borne primer and you could BURY it in lacquer sprayed wet with no problem, it was like magic.

Brian

My only problem with these explanations, and I do value them, as I am a newbie to this is I have 11 other pieces I painted with some or little body work where the bare plastic was exposed but did not exhibit the same wrinkling on any of them?
Sorry but I dont mean to hijack this subject but it was originally posted in 2009, :D

MARTINSR 04-27-2012 12:18 PM

Quote:

Originally Posted by egroothand
My only problem with these explanations, and I do value them, as I am a newbie to this is I have 11 other pieces I painted with some or little body work where the bare plastic was exposed but did not exhibit the same wrinkling on any of them?
Sorry but I dont mean to hijack this subject but it was originally posted in 2009, :D

LOLOL, I love that, how in the heck these things get dug up is beyond me.

On your question, if you have a number of pieces with the "same" sand thrus and what not and it only lifted on a few, then it MUST be as I explained it. You have to look at it this way, they all AREN'T the "same"! Think about it, there must be SOMETHING different between the different spots. One wrinkled and one didn't, there is SOMETHING different between the two spots, you CAN'T have the exact same circumstances and end up with a different result, right?

So, knowing that they MUST be different in some way, OR the way they were sprayed were different in SOME way. Standing there looking at your wrinkled up mess you need to think about this to determine just was is causing it. If all substrates are exactly the same, if every sand thru is exactly the same, well, now it comes down to how it was sprayed or products used. SOMETHING was different. Be it was sprayed wetter (this is often the case as just as humans we can have varied ways we could do something) because it was a smaller part, was it sprayed wetter because we wanted more primer because of some deep scratches we knew didn't exist in the other areas? SOMETHING could have been done in spraying.

Now, if all that is the same, there was absolutely nothing that you can think of was different in spraying then it was that there was SOMETHING different about the substrate. In a wrinkling situation this difference would likely be that the primer or paint was originally painted in before you sanded it was sprayed over a poorly sanded surface. So just these areas wrinkling are effected. But SOMETHING is different between the spots wrinkling and spots not wrinkling.

Brian

egroothand 04-27-2012 01:16 PM

Thanks Brian. What i meant by same was they were prepared the same. Two side panels off the bike had minor dings in the plastic that required sand down to the surrounding area to repair. These dings were about 6 inches apart so i sanded and area to combine them both rather than two seperate spots. Maybe not a good idea?? So after wiping down with Wax&grease remover and letting dry i hit it with the flexible primer sealer mentioned earlier. Came back about 20 minutes later and saw the ugly mess. I may have very well put it on to thick and will resand and try again. Thank you for your reply and tips
I gotta get this right afterall its the wifes bike and she is ready to ride and we all know if momma aint happy......

swvalcon 04-27-2012 01:22 PM

RM use to make a water bASED PRIMER I don't know if they still do. It came in a small 2 qt can that looked like a little barrel. You couldn't let it freeze or it was junk. Here in mn the delivery drivers had to keep it in side the cab of the truck in the winter time. Took for ever to dry when you put on the right mils but stuff worked great. You could use it on a fresh enamel job and put lacquer over it and never lift.

MARTINSR 04-27-2012 01:33 PM

When you cleaned it with wax and grease remover did you wipe on wet and then wipe dry with a clean cloth? If you wiped it then "let dry" it is possible this started the problem being wax and grease remover is very slow evaporating. If you didn't wipe it dry then let it evap a little too it is very possible the wax and grease remover was soaked up by something in the substrate being it the plastic it's self or primer or your filler or something. Then when it was primed being it was already wet and more than willing to fill right up with more solvent from the primer and lifted.

Brian

egroothand 04-27-2012 06:05 PM

2 Attachment(s)
That certainly makes sense to Me Brian. Thanks. Here it what it looks like. U G L Y.
Also a pic of my first attempt at Silver base coat before the Candy Green. PLease scrutinize if possible. I'd like to know of veterans if it looks good :confused:

MARTINSR 04-27-2012 10:54 PM

I don't see anything wrong in the second photo. But the first one isn't "wrinkling" at all, it's splitting. It too is caused by too much solvent. As it dries it splits like the mud in a river bed. This and lifting or wrinkling are two different animals.

Brian

egroothand 04-30-2012 06:11 AM

Thanks
 
Brian, before i sanded it the paint was wrinkled. It looked like a raisen lol. You are Correct sir. I seems i forgot that a rag it was using to wipe down after sanding had acetone on it from a previous job. It must have been absorbed to some degree i to the scuffed plastic and reacted when i sprayed the adhension promoter and flex primer. All good now thanks to everyones replies and lighter coats of the primer. Ready to lay down the green candy today. Fingers crossed.

egroothand 04-30-2012 07:05 AM

I really need to use spell check. Geeze


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