Question On The Infamous "Paint Dimple" On The C2 Firewall Side Facade

[Mark F.]

Re: Question On The Infamous "Paint Dimple" On The C2 Firewall Side Facade

MARIK
I owned a Pattern shop that made the tooling for foundries & permeant mold shops. For the sand foundries the tooling Is the male version to make the negative sand mold to pour the metal into. Permeant molds are the female tooling to pour the metal or liquid plastic in. There is pressure.to inject Aluminum or plastic so you dont need any pressure from the upper half to squeeze into recesses. <also called "injection molding ?

Cool beans, Kenneth,

I was in one of Ford's pattern shops back in the day...very exotic materials were used in some cases. Cateva wood ? or Cadeva wood ? can't remember the correct name, but it was heavily impregnated with hardeners to make it more dimensionally stable after shaped to the desiree part dimensions.

Did you use exotic stuff like that for the base materials ?

Was also in many plastic injection molding shops...mid-70's

[Rex M.]

Re: Question On The Infamous &quot;Paint Dimple&quot; On The C2 Firewall Side Facade

Just for further information on the dimple. I worked for General Tire & Rubber in the Fiberglass molding department. These marks as they appear are actually weld spots on the mold to make the part stay in the bottom half of the two part cavity mold. If the mold opens after curing and the part sticks to the top cavity it caused the part to fracture and be scrap. So the engineers placed weld spots on
many fiberglass parts to make them stay in the bottom cavities. Most marks are put on the "B" surfaces so you didn't see them. We were still making the C2 front upper parts in 2006. I think Eckler's purchased the original mold and still uses it.

[Don T.]

[Mark F.]

Re: Question On The Infamous &quot;Paint Dimple&quot; On The C2 Firewall Side Facade

If it's a male projection, the underside should have a matching "hole" Agreed... I've never looked underneath, so don't know if it's there or not. nor I

I think it's a flaw in the mold probably and was the result of the resin and chopped fiberglass ? pooling (or squeezed in under pressure) in a divot. That Chevrolet didn't catch and fix it early on is par for the course considering they let the waaaaay more obvious valve cover flaw go on for years. Yeah, that's pretty amazing because of how noticeable it was !

Also, all of the above would have been MUCH, MUCH easier to fix than the coupe door-to-roof fitment screw up.

[Mark F.]

Re: Question On The Infamous &quot;Paint Dimple&quot; On The C2 Firewall Side Facade

Just for further information on the dimple. I worked for General Tire & Rubber in the Fiberglass molding department. These marks as they appear are actually weld spots on the mold to make the part stay in the bottom half of the two part cavity mold. If the mold opens after curing and the part sticks to the top cavity it caused the part to fracture and be scrap. So the engineers placed weld spots on
many fiberglass parts to make them stay in the bottom cavities. Most marks are put on the "B" surfaces so you didn't see them. We were still making the C2 front upper parts in 2006. I think Eckler's purchased the original mold and still uses it.

OK, Rex, thanks much for that info !

For a part that large, wouldn't there need to be more than just one weld spot to accomplish what you are saying needed to be done ?

[Tim G.]

Re: Question On The Infamous &quot;Paint Dimple&quot; On The C2 Firewall Side Facade

I've owned a number of 67's and original cars tend to always have the bump. The only original paint car I've ever owned that didn't have a bump was in the 66XX range.

[Jack M.]

Re: Question On The Infamous &quot;Paint Dimple&quot; On The C2 Firewall Side Facade

Some 1967 VIN & DATE ranges are listed in this PDF from David Burroughs... ORIGINAL cars, but WITHOUT the PIMPLE.

[Patrick B.]

Re: Question On The Infamous &quot;Paint Dimple&quot; On The C2 Firewall Side Facade

If there are cars with original paint and no dimple and all front surrounds came from the same mold, the only possible conclusion is that sometimes the dimple was sanded off during paint preparation at the factory.

[Rex M.]

Re: Question On The Infamous &quot;Paint Dimple&quot; On The C2 Firewall Side Facade

There probably was but they might be on the bottom side you can't see. It's surprising St Louis didn't sand the spot off and they may have on several. It's in a area that would be hard to sand off.

[Owen L.]

Re: Question On The Infamous &quot;Paint Dimple&quot; On The C2 Firewall Side Facade

If there are cars with original paint and no dimple and all front surrounds came from the same mold, the only possible conclusion is that sometimes the dimple was sanded off during paint preparation at the factory.

Whenever Steve was on the line, he razor-bladed off the dot because he really cared for Corvettes — his uncle owned a fuelie '57 and Steve's dream was to own a C2. He wanted them to be perfect.

[Kenneth B.]

Re: Question On The Infamous &quot;Paint Dimple&quot; On The C2 Firewall Side Facade

MARK
Yes we did but mostly Mahogany. Lot of patternmakers that worked in the wood shop got cancer from milling & sanding the Impreg from the plastic bonding material.Now thy dont make patterns anymore. just CNC the metal.

[Kenneth B.]

Re: Question On The Infamous &quot;Paint Dimple&quot; On The C2 Firewall Side Facade

You are correct..

[Kenneth B.]

Re: Question On The Infamous &quot;Paint Dimple&quot; On The C2 Firewall Side Facade

Just for further information on the dimple. I worked for General Tire & Rubber in the Fiberglass molding department. These marks as they appear are actually weld spots on the mold to make the part stay in the bottom half of the two part cavity mold. If the mold opens after curing and the part sticks to the top cavity it caused the part to fracture and be scrap. So the engineers placed weld spots on
many fiberglass parts to make them stay in the bottom cavities. Most marks are put on the "B" surfaces so you didn't see them. We were still making the C2 front upper parts in 2006. I think Eckler's purchased the original mold and still uses it.

A weld spot on the mold would leave a indentation NOT a raised dimple.