DansYellow66

Recieved my Cobra replica kit and been taking stock of the body work and straightedging panels. It looks like I will have to skim coat most of the door, hood and truck panel joints to flush them up a little better and I found a couple of undulations in bigger panels - probably nothing more than 1/8 inch at the absolute deepest. My question is - does anyone think it's best to initially skim the deeper areas with a fiberglass reinforced body filler first (for strength), knock that down and then skim everything with a thin layer of something like Rage Extreme? Or just go with straight premium body filler up to 1/8 inch thick? I'm leaning towards the latter and that's pretty much what I did with my Corvette 18 years ago with no problems to date - but since this is on top of gel coat instead of under gel coat, I thought I would ask for current opinion.

Thanks

Dan

1snake

On my Cobra, I sanded the whole car, skimmed coated the areas that needed it with Rage Extreme, sanded those areas, shot the whole car with Featherfill, blocked it, primed it, blocked it, sealed it and painted it.

Jim

DUB

I presonally/professionally prefer Fiberglass/Evercoat Vette Panel Adhesive/Filler ..part number 880 (gallon size). It is a heavy bodied filler and is much stronger than any RAGE product...if strength is what you are looking for. If you need a tutorial on using the 880...if you choose to use it...just PM me and I can give you tips in making the process go a bit easier...due to the Vette Panel adhesive gets hard as heck when cured....unlike most other filler on the market that are 'lightweight". Literally( the 880) ...it is my choice in fillers when doing repairs.

"DUB"

1snake

Vette Panel adhesive is good stuff (I prefer Duraglass, much stronger) however, the OP is talking 1/8" max. and not structural. Rage Extreme is self leveling, doesn't pinhole and is the easiest sanding product on the market. Just my humble professional opinion.

Jim

DansYellow66

Yes, 1/8 inch max (maybe just slightly deeper but over a very small area). On average I think I'm looking at 1/16 inch or less. I haven't scuffed the gel coat up yet. I plan to block it first and then scuff up any low areas that blocking misses. That will probably bring the thickness and area down a little more.

I do have a couple areas around the cockpit that I need to fill in behind the lip so I can radius the edges to mimic the original cars. I was thinking of getting a quart of 3M Marine Blister and Repair Filler (HSRF) that seems to be popular with the Cobra crowd for things like this???

What would you initially block the gelcoat with to start smoothing? I hate being more aggressive than necessary and just ending up with deep scratches and holidays through the gel coat, so I was thinking 180 grit.

1snake

The very first thing to do is to scrub the body with Scotchbrite pads and either lacquer thinner or acetone to make sure all the mold release is removed.

jrm747

i would sand thru the gel coat on areas you intend to use the rage. i use z-grip by evercoat. sands a little easier to me. anyways, i would trust putting it on top of the gel coat. thats just the way i was taught though. i could be wrong. i wouldnt sand filler with 180. i usually use 36 to get it close then 80 to finish it off. then i will skim coat my filler with metal glaze or easysand. then i will 80 that till it gets close, then finish it off with 180, then 240 or 320 before priming. i always had a hard time getting filler smooth using lighter grit papers. i have found, for me, that if i let everything dry well in between coats, i dont get minimal shrink back. i would allow the primer to dry for a week or so if not longer also. maybe even do some initial sanding to open it up and let it breath before doing your final blocking.

DUB

...that mold release can come back and 'bite" you...if you do not take efforts to get it off. I prefer acetone.

Whatever product you plan on using to fill in the area that you want to fill in...I prefer using a product that gets hard and will not shrink. That is why I use Vette panel adhesive. There are so many fillers that will work in your case...I just like the filler to gets hard and feathers well...which Vette Panel adhesive does do that...very well.

But to each his/her own.

"DUB"

Barryga

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Before I totaled a body with lacquer thinner, I would call the manufacturer of the body first.

porchdog

ppg first clean dx330 is excellent for this . wash twice before you ever sand it with anything.

DansYellow66

Yes, I was planning to scrub down the body first. I have a half gallon of Prep Sol that I planned to use with a 3M pad. I could do a wipe down with Acetone also.

Thanks

1snake

I've been using lacquer thinner and acetone on fiberglass bodies (Corvette and Cobra & GT 40 replicas) for over 30 years. No problems so far.

Jim

porchdog

why not just use a cleaning solvent made for the job ?

34RedRage

hey porchdog, welcome back!!!!!

1snake

Since I'm not familiar with dx330, I looked it up and found this:

A very slow evaporating cleaner. It is also very weak, and actually only mineral spirits or mostly mineral spirits. It is a good cleaner because it is weak and will not attack any soft substrates like lacquer, uncured enamels, etc. But it will not clean a lot of strong contaminants like vinyl treatments. When you have a reason to believe there is a particularly bad contaminant you may need to go to a stronger cleaner. It is very slow evaporating so you have to be sure it is fully evaporated after wiping before you apply any paint product over it.


Definitely NOT what you would use to remove mold release from a fresh body.

Jim

porchdog

ppg has only one cleaner stronger. dx440 which is an industrial strength for road tar and undercoating. never had to use it. mold release is wax or pva . since pva can etch the molds it is not used in fiberglass parts molds. by 330 or 440 staying wet longer it has a better chance of floating the contaminates and wax so they can be removed.

the reason i always recommend against thinner is most of these guys are not pro painters. they will go to napa and get a 5 gal can of wash thinner. which is not lacquer thinner by any means . it is just recycled solvents. who knows what is in the can. there could be acids or worse in it. these are not compounds you want to soak into raw glass.

factory five will suggest you buy release agent cleaner from west marine . it always good to ask the tech people for the brand paint you are using what to use. i my case i use spi products which highly recommends against it.

i never claimed to know it all but just like that little band from texas " i know a little "

Barryga

Snake!,

First, so there is no pissing match, it makes no difference to me if you use lacquer thinner or not, you have been damn lucky or have not done many corvettes.
There are people that still use lacquer primer also and get away with it to a point.

Lacquer thinner= its a genetic name and NOT what it use to be, real lacquer thinner would be say, PNT90, DTL105 and I'm sure you are not paying $80-100 a gallon for cleaner and even it can cause problems but that is another essay as to how and why.

The 5 gallon thinner you buy from the paint jobber to clean you gun, is NOT lacquer thinner at $30-45 a 5 gallon pail and its made to clean guns because no one uses lacquer anymore and the good companies say on the can "not for paint use" Why? I don't care if they say virgin solvents or not, they are as virgin as Madonna is, reclaimed solvents or recycled to keep the price down. Usually they contain two solvents where PNT90 may have 8-11 for the proper ladder scale required.

5 years ago I spent 30 days with the GM of a large Chevy dealer trying to save a front end on a new vette where the power steering hose broke with 75 miles on it and the body shop helper cleaned it with thinner, that had frozen (44 degrees) and the solvent reverted back to the original acid state from with the solvent is made, could not be saved, I tried every cleaning way I knew.

Right now there is a batch that is eating the aluminum cups on the paint guns when they clean it, sorry there is no Paint solvent going to eat aluminum, only an acid.

NO paint company, NO body maker I know ever recommends lacquer thinner as a cleaner.

Mold release comes in different forms but usually a wax derivative and that is what wax and grease remover is for-wax.

Without writing a book, the above is short and condensed and hope this helps you understand why you need to stop using it now, on metal or fiberglass.

Good luck with it but it is not right to recommend it to other do-it your-self guys, as they have enough issues to overcome painting a car.
Best of luck.

porchdog

waaazup big guy . you need to come by streetrodding.com sometime.

34RedRage

i will look you up there, i have the same screen name there as i do here!!!!

1snake

No pissin' match. I don't use lacquer thinner as a cleaner before paint. The OP is talking about a Cobra body fresh out of the mold, NOT a already painted Corvette.
I don't know if I "lucky" or not but I have painted many Corvettes. Cobras' present their own special problems not associated with Corvettes and I've done lots of them as well.
Use whatever you're comfortable with and I'll do the same.

Jim