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Hey all,
Prepping my firewall for paint and came across a question about the sealant that appears to be slopped on the fire wall. Is it safe to scrape this stuff off, or better to be sanded off?
Hi CLJ,
The area of the firewall shown in your photos APPEARS to have been damaged in some way.
It appears some sort of 'material' has been poorly applied over the damage to do a repair.
What you do at this point depends on whether you want to address the damage and do a proper repair or not.
It MAY be that what's been added was part of a 'modification' to the firewall or an attempt to stop a leak in that area.
Looking at that area of the firewall from the interior of the car may give you an idea of what's going on there.
Regards,
Alan
That area of the firewall has a lot going on but the fiberglass itself was smoothly molded.
My 79' had the same stuff slopped on. I agree with Alan that it was an attempt by GM to seal the multitude of leaks these cars suffered from. It is brittle and I was able to scrap it off with a putty knife.
It looks like it was poured on after the rubber grommets were fitted
using a scraper on that stuff will have a limited success , as its usually as hard as concrete , you might be lucky and it shatters and flicks off .I would try a scraper first but keep the blade parallel to the surface so you don't pierce the glass .If scraping by hand doesn't work ,I would be very careful of using a hammer to knock the scraper , you might just start taking fibreglass away with the mess.
A die grinder with a sanding disc on will eat that up quick , but there will be plenty of dust and if you have never used one on glass you can go through the firewall panel in an instant , plus you have tight corners where the wheel cant get into ,so that means breaking out the 30 grit and get at it
As Alan says check the back first for signs of a repair .
[QUOTE=bazza77;1596733718]It looks like it was poured on after the rubber grommets were fitted
using a scraper on that stuff will have a limited success , as its usually as hard as concrete , you might be lucky and it shatters and flicks off .I would try a scraper first but keep the blade parallel to the surface so you don't pierce the glass .If scraping by hand doesn't work ,I would be very careful of using a hammer to knock the scraper , you might just start taking fibreglass away with the mess.
A die grinder with a sanding disc on will eat that up quick , but there will be plenty of dust and if you have never used one on glass you can go through the firewall panel in an instant , plus you have tight corners where the wheel cant get into ,so that means breaking out the 30 grit and get at it
As Alan says check the back first for signs of a repair .[/QUOTE
I cleaned mine up with a putty knive and used accetone and a scotchbright to clean it up brfore I repainted it. My 70 was bad also. The wiper bay looked like someone poured a bucket of that stuff in there.
I cleaned mine up with a putty knive and used accetone and a scotchbright to clean it up brfore I repainted it. My 70 was bad also. The wiper bay looked like someone poured a bucket of that stuff in there.
Yes its a good feeling to get that area done and crossed off the list
Hi,
It was these areas that made me wonder about damage. It could be that the material at the right arrow is 'bond' that squeezed out. But I'm surprised how much there apparently is.
I agree that the pumpable black sealer that was used was indeed very sloppily applied, especially around grommets.
Regards,
Alan
Hi Alan , the OP pics look just like the sides of my 69 plenum area (around the foot vent area ) where the sealer was just kinda poured on and looked like a lava flow with the air bubbles in them ,travelling down.
How about heat gun? Or maybe just hair dryer? That prepped pic of that wiper channel in that firewall are almost so pretty it's a shame to put a nose on and hide them.
How about heat gun? Or maybe just hair dryer? That prepped pic of that wiper channel in that firewall are almost so pretty it's a shame to put a nose on and hide them.
The trouble with heating that stuff up is while it makes the mess softer and more manageable it also makes the glass panel softer and easier to damage. That's just my opinion though.
I also had that stuff in the wiper bay, I was lucky and able to 'chip' it out with a screwdriver and hammer and it looked good as new. I then had someone put a new even layer of sealant to stop the leak that was there.
Hey all,
Prepping my firewall for paint and came across a question about the sealant that appears to be slopped on the fire wall. Is it safe to scrape this stuff off, or better to be sanded off?
Thank you all for the advice, I am going to sand this down and smooth as much as I can.
Hi,
Removing all the excess sealer and glop, but leaving the 'grain' in the fiberglass surface, is an option for someone looking for a more original appearance.
Quite a bit of work... but not as much as the 'smooth' look that BZ achieved.
Regards,
Alan
Hi,
Removing all the excess sealer and glop, but leaving the 'grain' in the fiberglass surface, is an option for someone looking for a more original appearance.
Quite a bit of work... but not as much as the 'smooth' look that BZ achieved.
Regards,
Alan
I agree I’m leaving the grain, I was able to use a scraper and sander to get mine down to the grain I think it looks original also
Last edited by CLJonesVette; Mar 13, 2018 at 04:46 PM.
Hi CLJ,
As I posted....leaving the grain is a good option.
But.... b77's photos show how good smoothing the fiberglass can look too!
It's really a matter of preference.
Regards,
Alan
I was able to use an oscillating tool with a scraper on it to get the majority of the crap off the firewall and I switched to a triangle sanding pad to cut through the remaining layer.
Firewall prep
