urethane clear over lacquer color coat?

Can we do that?
Adhesion proplems?
Gas off or solvent troubles?

 

Yup - it's been done. Either during the re-coat window of the lacquer (check the MSDS), or well after, with the lacquer scuffed with 800 or finer.

But a better question is - why did you use lacquer?

Also, could you not just buff the lacquer, or go with a lacquer clear...?

 

The why is a long story and has its own thread
http://www.jalopyjournal.com/forum/showthread.php?t=782657.

It will be a new paint job,

It was suggested to put 2 coats of lacquer clear over the fresh color and let that gas off a few weeks.
Sand the clear then urethane clear over that and use the mechanical bond . Thereby eliminating adhesion and solvent problems and locking down the color if there were to be a problem.
Seems like very sound advice and reasoning but IDK ?
So I'm asking here too.

 

Gonna say dont do it.....i keeping visions of laquar with chromabase clear over it from back in the early 90's.......didnt stay on too well

 

i have never personally sanded the laquer clear and urethaned over the top of that, but i'm with brandon, i would not take that risk. maybe some one here has had success with it and can chime in.

 

Lacquer is stable under catalyzed products. I would definitely let it gas off first though.

 

I figure there will be a 50/50 split on opinions about this .

 

Does this ^^^^
Sound like a good way to go about it ?

 

when bc/cc started out we always put urethane clear over top of lacquer,never had any problems..this was in a production shop..

 

I am sorry to hijack, but I have a very old lacquer paint job I would like to protect. Can I spray urethane on top? Will it stick long term?

 

OK what was the process ?
Was there a gas off period ?
Or did the clear just get applied after the lacquer flashed ?

 

No you ain't sorry, you just figured that its easier to get forgiveness than permission.
Why apologize with "sorry " for something you meant to do ?
See the word "but" in your post ? Here's how "but" works -
this is what you want to hear BUT this is what's going to happen or this is how I really feel
start your own thread

Just kidding

 

The paint reps say don't but I will say this I have done it on a couple of Harley's only reason being is when you go into harley and buy base for a factory color it is lacquer but on a overall paint Job ? You can clear bare alum or steel. It will hold up till it gets a chip then all hell brakes loose if I were gonna do it I would let it flash scuff it with 800 or a 1000 grit then clear it sanding should help it bite in mechanically cus that's the problem there is not much chemical adhesion with lacquer and urethane clear over top it will probably work but would be worried about it chipping later then clear peeling use a slower activator in clear to get as much chemical adhesion as possible

 

'80's we were covering lacquer, enamel and GM B/C's with Duponts Urethane. Most 'thanes are plastic. Prep is always key for success. Remember to protect your self. And it dries slow, with evil gases.

 

Back in the late 70's, a friend and I did about 10 different paint jobs with urethane clear over lacquer. We never had a problem with any on them. The problem back in those days was trying to get the final product to lacquer like finish; which we just weren't able to get the gloss that we were looking for. Now days, the compounds are a lot finer than what they were back then; which is most of the problem we had then. We would wet sand the buff, but the finish at best was just hazy.

 

I look at it this way.... it should work, and others have done it. That being said, it will only be a "mechanical" vs. "chemical" or "mech/chem" bond.

Best would be to spray out an old door using the primer, sealer, lacquer you intend on using, then a urethane clear......set it outside for a month, see what happens (does it get solvent pop, milky colored, look like it may de-laminate, etc., etc.) If it does work, don't change your steps.

I would try it.... but it is not my car, and block-sanding efforts... LOL

BTW I saw your other thread a few days back. Are you still having issues matching the paint you want, thus this question? I would try to find a jobber or make friend with a custom paint shop and see if he will make up some base for you....would hate to see you get the color you want, then have the clear come off like an '89 ford when the UV attacks the base...

 

I did an early Jag back in the 80's like this. Shot the lacquer color coat, let it dry for a several weeks. Color sanded it with 600 wet, then prep and cleared with S and W 650 urethane clear. Did a final cut and buff on the clear. Looked really nice. The car was around for a few more years and still looked good. Use good thinners and a water separator when shooting the lacquer though.

 

Well chopolds has said he would be pretty sure to match it.
I'm in the process of making another sprayout sample to send him.
Was talking this morning about doing a whole fender and taking a ride there with it.


I've stopped and talked to a few different shops the past 2 days.
Not much luck.

 

I have asked some paint guys this before and thay said dont do it but thay may have just been trying to cover there ass. seems like you need to be an alchemist to fuck with paint anymore.

 

I painted my GTX with lacquer and a clear enamel over it in the 80s it lasted about 10 years and then started to look shabby. I have also painted lacquer with a urethane clear. Its 2013 avoid lacquer if possible and use a urethane single stage or urathane base coat clear coat you will have a more durabale stable end product. Just my opinion, you dont want to do this twice. Dave

 

Also be very wary of the scratches showing,you are not supposed to sand your "base" on a BC/CC job,first car i ever did in BC/CC i had some little nibs of dirt,paint guy said just sand them out and clear over it?,big big mistake,every scratch was magnified 10 times over,had to redo that one.The old Dupont base coat,HI-TECH was the name i think?,it was a laquer based paint,it was crap though,never liked it for large areas,was fine on small spots.if you sand the car i would use no coarser then 800-1000 grit paper,use it wet too. Harvey

 

If you sand a base coat, it needs to be resprayed before the clear coat.
Same thing with lacquer, only easier - if you need to sand the color coat it needs to be resprayed before the clear coat.

 

31vicky, but, butt!

 

But butt what ?

 

flames on chubbie are house of color lacquer, over urethane,and cleared with urethane. look great after about 12 years. they were painted by a guy now liveing in Kamiah, Idaho. Don "villio" Nummi. i took it to a PPG body shop to have it cleared and they called the PPG rep. he came over and chewed me out, told me to get my car out of there! told the body shop manager to NOT clear over that house of color lacquer or else!! made a real ass of himself!!! don't understand. I've never seen or heard of a company repainting any thing under warrenty in my short life.

 

OK for the "NO" crowd - why no?

 

if I was to the point of paint , I wouldn't want to run the risk of a "issue" with adhesion of clear. i'd rather do it once than to chance it and have to redo it twice....


just because you can ....doesn't mean you should.

 

Yeah, you can pull this off, but why? You're asking chemmies and solvents to do jobs they weren't formulated to do
Back in the 70s I did van conversion paint jobs, lacquer in three, four or five different shades/colours over brand new acrylic enamel (brand new vehicles). Lacquer was baked with a heat lamp so back taping and multi masking could be done same day. Once all the tape and masks were pulled we'd over shoot in Centari or RM SuperMax with a shit load of hardner for quick delivery. The jobs seemed to last 'bout two-three years in the California sun

Hey Happy,

Ain't no way in hell I'd overclear an older lacquer job! The solvents and acids used in hardners would pop the old binder in the lacquer and then you'd be '' lightning struck and camel fucked "


" You can see happiness stagger on down the street "

 

In the 80's I had success with Harley lacquer candies as a base, 2 coats of clear lacquer with a 600 wet sand, then 2 light coats of PPG 1900S Bonding Clear, then urethane clear.

But, that was then, this is now.

 

Seems like a lacquer job back in the day would get a good ten years, of outside exposure before some fading or drying out and cracking and chipping. I have heard several times that lacquer will do the same under base/clear top coat. SO, you then have a 10-12 year span paint job. I had a 67 camaro painted in '90 with base/
clear and sold it last year, and I was still shining like a diamond. Sell the lacquer paint to the corvette guys that want it for what it is. What color do you have in lacquer?