Paint question.

[Simon TR4a]

A recent racing accident has meant I will probably be putting a new bodyshell on my TR4a, and it will obviously have to be painted.

I know very little about paint and need some background info and advice. My understanding is that prewar cars were painted with an oil-based lacquer finish, later an oil based enamel, modern cars a 2 part process of water based colour coat followed by clear coat, and that this finish is shinier and tough, but difficult to repair small chips and scratches.

I have been told acrylic enamel is a good choice for someone peferring an original looking paint job, as opposed to the ultra shiny new tech paints.
I really need an education in this if someone can point me to a website like "automotive finishes for dummies"!
Thanks, Simon.

 

[screenprinter]

Simon,

I've done a little painting so I'll share what knowlege I have..

Modern 2 part paint systems share one great advantage with old style laquer jobs - After you apply the color coat which will look dull and you apply the clear coat , if you have slight imperfections in the clear they can possibly be wet sanded and new clear applied over the top - Old laquer jobs were famous for their deep look ( the old "13 coats of hand rubbed laquer" bit) because each coat was dried and sanded and more applied, and repeated until the surface was perfect, or at least very smooth, Then Polished with a buffer and compound to produce a finish which looked quite like a Revel Plastic Model - Nearly Flawlessand very deep.

Acrylic enamel is good paint and fairly easy to apply, AND you're right - it does look more like original paint used on LBCs because it looks more like solid color as opposed to color under a layer of glass like clear coat or laquer jobs, but you have to be careful of a couple of things:

Don't put on too thick a coat because enamel flows for quite a while - You could really lay it on the body, it looks great, you go home and sleep and the next morning there are "Lace Curtains" or sags/runs all in the finish because the paint has flowed via gravity all night. This is particularly dangerous when the weather is hot and humid - the paint takes longer to Tack dry therefore has a longer time to sag.

Second, If you get dirt in the finish, "Fisheye" which is usually from oil or silicone contamination on the prepped body, and looks like oily little craters in the paint, "orange peel" which usually occurs if you use too high an air pressure at the gun, resulting in more air, less paint, or any one of a number of surface imperfections you'll have a tough time sanding out sags, orange peel, fisheye, etc because enamel doesn't fully cure for a LONG time - It actually flows for MONTHS after the car is painted. It remains slightly soft ( Eventhough dry to the touch - much like panes of glass in a window) and as such is very hard to sand satisfactorily.
There are hardeners you can add to certain enamels which minimizes this effect but you still have to be careful not to let the paint run, etc beacause it is still suseptible to these effects while the hardener takes effect and the paint dryies, and because it'll still be a pain in the a** to rectify these errors.

Laquers and base coat/clear coat systems dry faster and harder and as such lend themselves to "fussy finishing" if you want to go that route.

A third category of paints to note are the catalized enamels such as Imron and Amerflint - If they still exist ( not sure - the EPA may have passed laws against them because of the health hazards the use of these paints pose) - This is a two part paint - the paint proper and a catalizing hardener which you add when thinning the paint to spray - It applies like regular enamel but has a limited "pot life" and when that time expires it VERY quickly gets harder than Chinese Arithmetic - Certainly can't leave it in the gun unless you want to chuck it when you're done.

These are very tough paints - Imron is used quite a bit on commercial aircraft - and have a good shine and last for a long time, but the downside is, you better do a good job the first time because it's hard as H*ll to sand the goofs out of this stuff. Equally important is the hardener used contains the ingredients found in Super Glue and is very nasty stuff indeed - Where you can get away with a good OSHA Approved respirator with the first two type paints you really need a good fresh air supply respirator for painting the cataized paints - they really are dangerous and the effects may not show themselves for a while so your really not aware of anything worse than your nose hair being stuck together big time.

So now that I have thouroughly confused you I'll close knowing that somebody in this forum most likely has more knowlege of what paint types were used and when ( My knowlege came from painting choppers and hippie vans in the 60's) and will no doubt be along shortly.

Hope this gives you some help!

Bob M.

 

[MrBlueSky]

Try www.autobodystore.com , the guys on this very active message board are long time pros and will help you with any question you have. They literly tought me how to paint, now I get perfect $5000 paint jobs for just a few hundred bucks and some simi-hard work. These guys will encourage you to do it yourself and give you the confidence you need, if you would like to go down that path. If not they will gladly help you with dealing with your local body shops so you can get just what you want.

 

[Geo Hahn]

Also some FAQ's here: https://www.paneldoctor.com/FAQ/faq.htm

 

[MDCanaday]

Acrylic enamel is not a choice its a disaster. Prep is the real problem (media blasting???) if you dont use a good polyureathane enamel dont paint it. How bad is your tub,?? is it past repair.

 

[Simon TR4a]

Thanks for all the advice, guys, looks like urethane enamel is the way to go. I have also been told elsewhere that it is somewhat resistant to damage from brake fluid, so another plus!
The front of the car is pretty bad, frame bent, damage to valance, grille, both left and right front fenders and inner fenders, radiator, fan, motor pushed back to firewall.
I think cheaper to replace than repair- a shame as it was very nearly a rust-free car!
Simon.

 

[TC1]

Hey,
I dont know if you have already painted the car but Amer Flint II (Herb Clann's second version of his paint) is still available American Laquer was bought out by Lilly and then PPG so you could check with them. The safety issues are easily taken care of if you wear the proper respirator mask. The chenist also had a final version of the Flint series that was named Hydro Flint. It was produced at the end of Lilly but, it should still be available if you are interested in using it.
On a side note I am sure that Mr. Clann would be happy to know that so many years after he retired people still use his paints. I am a little biased since I am his grand son but, he enjoyed working on the cars and would be thrilled that people remember it.