Two questions for the gurus:

My body is ready to come off the frame (coupe), is going on a rotisserie, and getting sandblasted. The 1/4's are already cut out (3/4 cutout) so the blaster can get inside the panels...Do I have to worry (or should I) about bracing the body for being on the rotisserie?

Two:
One of my big problems w/ non-factory paint is the huge chips that come when normal road-wear is exhibited on a driven car..factory paint doesn't do that, and even expensive jobs I've seen do the same thing. I've been informed by at least two painters that my idea of using 'flex agent' in the paint is a good idea, and won't harm anything, but the flex needs to be added to everything that's underneath, through to the top clear. Is that true? and Is flex a good idea?

I plan on racing this car at well over 150 in less than a couple of years (restore schedule allowing) and don't want the paint looking like crap if I choose to drive it to events. I just want to do it right the first time.

Thanks in advance!!

JR

Flex additives are intended for use on "flexible" parts such as eurathane bumper's on new cars etc... To prevent chipping in rocker areas, use a "smooth" rockerguard coating. It goes on thin and smooths nicely and is barely noticeable by the trained eye. I have seen hard panels coated with "flexed" paint and the paint has failed over time...

Check out the 3M link below for more info on the products available.

3M Scotchgard Products (http://cms.3m.com/cms/US/en/2-168/czrRFFU/view.jhtml)

Hope it Helps

Thanks. I hadn't heard of the paint 'failing'...it was just a thought.

JR

The flex agent in the paint for metal panels is actualy a very good idea. Akzo Nobel suggests the use of their flex additive on sheetmetal and from what I've heardd from the shops is the paint has been holding up very good with far less stone chip complaints. Also, the hardness of the primers used also greatly affects how easily the paint chips, soft primers allow the paint to chip very easy-so it's not always the paint that causes the failure.

From what I understand, it's not necessarily the hardness of the primer, but the thickness and the different natures of the primer and paint. My belief (concurred by at least a couple of paint specialists that, by the way, had not tried this) was that using flex on everything from the primer on up would make the paint have unity with the metal more than just a bond, and might actually 'flex' rather than 'flake' when impacted. I've always been impressed at how durable paint on a flexible bumper is...that was the basis for my thought. Conversely, I've always been dismayed at the severe damage from a rock chip or door ding on 'paint-shop' jobs.
There's no doubt, as I wish to drive my car in competition, that I'll get chips...I just want the damage minimized to that which I'm used to on 'new car paint jobs'.
I just don't want to paint my whole car w/o hearing both side's input on this.

Anybody else??

JR

I guy that I know who is the main painter at a local new car dealerships body shop is also an advocate of using the flex agent on the whole car. His reasoning is basically all the same as badbob stated. I've been considering doing the same on my car when the time comes.

Although not metal, but not urethane either, I painted my 1978 Corvette in 1989 and used flex in all the color and clear. It's not driven that much, but it still gets great complements on the paint. Won a 3rd place recently at an all Vette show with nothing but a wash job and a quick hand polish. No other detailing...not even tire dressing.

Sorry but replacing those quarters with the car on a rotisserie is a stupid idea. All welded panels should and need to be replaced with the car sitting on the frame with the suspension loaded just like normal conditions.

By placing it on that rotisserie you are putting stress on that car in places that shouldnt be.
Whacking out those quarters could lead to some serious alginment problems down the road.

Am sure some guys out there do this procedure everyday with no problems, but not me not any one with a head on their shoulders.

Correct me if am wrong but dont the flex additives "disappear" after a certain time frame? PPG flex is not a perament additive, if I remember right after around a month it evaporates out. I do recall some Spies Hecker painters saying that their flex additive is a lasting additive.

Be something to look into before wasting your money on flex additive.

Clarity:
1/4's are cut out, body goes on rotisserie for blasting, body goes on frame 'mock-up' (old frame) for body work.

Acceptable?

If I can 'find' one, the roof skin is getting replaced as well. I intend on having the soda-blasted doors and trunk lid for my guy to make sure everything lines up.

My question still, is... 'Does the body need braced simply for being on the rotisserie both during transport and while blasting with the 1/4's being cut out?' and, now that I think about it, 'Where would be the best places for the bracing?'.

I haven't asked my body guy, as I'm not sure he knows any more than I do, as he's used to working on the body 'on the frame'.

Anybody?

As far as the flex 'evaporating', I'd love more input on that. It's my understanding that flex agent 'elastizes' the paint, making it more 'flexible' and 'impact resistant'. Curious about the ambiguous replies, I did some research:
http://www.zymol.com/detail1.htm
Additional research clued me in on the fact that flex agent is, for a fact, just for plastic parts that are 'not rigid', and may accelerate degradation of the paint. Apparently, polyurethane 2-part compounds are better, and don't require flex, as I understand it. So I'm done with that. The paint I'm 90% decided on is a tri-coat. As long as I stick w/ the same brand, and prep correctly, I'm sure all will work out. As I'm doing all the prep work in cooperation w/ my body guy, and doing all the etching/priming/sand prep myself, I wanted to make sure I did for the paint shop that which didn't screw things up.

Anybody else on the body bracing?

JR