RickDett

I am getting ready to put new carpet in. I've been doing some water leak testing on the firewall which I suspected had a small water leak. It seems the sealer between the firewall panels is leaking on driver and passenger sides. See pics. So I did some dental work and removed the loose cavity and ended up with an 8" inch long 1/8" wide gap that I need to seal. What is the proper sealer (or next best thing) to use to bond and seal these panels?






(On the dark picture light is shinny thought from underneath as a visual reference.)

DUB

This is what I use.

http://www.crlaurence.com/crlapps/sh...&ModelID=19965

You could also use this.

https://www.semproducts.com/repair-s...ge-seam-sealer

When I repair this area ...which does happen more times than you might think. I do much like what you did and pick out all of what I can get out. I them look and see if the metal is rusted. More times than not...it is.

I try to use products that will aid in getting the rust off. I make ALL efforts to centralize the rust removing product to stay on the metal side as much as I can and not just pour it in the seam. Knowing that this product is a phosphoric acid based product. I do not feel good about it getting into the fiberglass and thus possibly causing whatever I apply in the seam to not stick to the fiberglass. So it is toss-up....either try to stop the rust carefully...or do nothing at all and HOPE that whatever you pump into the seam will adhere to the rust...which I can tell you...normally does not work for long. If I use a the acid....I then I dribble epoxy primer in that seam and let it flow out into the car...which does happen.

Then I will normally use the CRL product and let it flow into the seam. Some times it can flow down and drip. If it does...after the first application has 'skinned over'. I apply more.
When I get this area filled in....and knowing that I did prep the fiberglas well and it has the epoxy primer on it that I previously dribbled down into the seam. I pump more of the CRL products and get it to flow and look good so the water will shed off of the area.

I am completely aware that you may find that there are some areas of the seam where the fiberglass and steel are really tight together due to the rivets. I understand this..and you may ask how do you deal with any rust issues there. Unless you being the process of removing rivets and get between the two parts...there is none that I can think of. And I also understand that what I wrote in an above paragraph may seem to be jibberish stuff. And it may be just that. Because if there are ares in your cowl that are tight...and you can not treat the same as the areas that are wide...they why worry about the above mentioned step at all. That is when you choose how you want to do it.

I am only giving you the steps in how I do it on the a Corvettes I work on. And yes..>..I have had a few Corvettes that were so badly rusted that all I could do was pack the 3M strip caulk in that seam and seal over it with CRl product. It was pointless in doing any more because the 'beginning of the end' had already started. And the costs to do it right was not what the customer wanted to pay.

I mentioned the SEM product..and it also works well. it is catalyzed...so if you choose to use it and try to get it to go into the seam with a spreader or spatula...you better work quickly due to it sets-up but yet remains flexible and can be painted on. Making sure your exterior surface are is correctly prepped so it will adhere is also imperative. Contact SEM directly if you have any questions. They have great tech support department. It does requires special gun to apply the SEM product...but in your area you may have a SEM rep that may have one to loan you so you can use their product and return the gun when done.

I hope that this was of some help.

DUB

RickDett

DUB, Thanks and yes very useful all of it. I didn’t think about the rust as I should have, I will address it. The rust is not of a significate area but never the less prevailing, the 'beginning of the end' is inevitable, they is no way to remove all of the rust without disassembly. So weighing it out I am going to bandaid it with your product recommendations and save removing rivet and disassembly for another day. Again I will focus my attention on preparation as much as possible. What’s your thoughts regarding POR15 rust preventative?

Thanks for the recommendations.

RickDett

DUB,

I am going to go with the CRL Black Pint Windshield and Repair Butyl Sealant because it seems like it should flow into tight cracks better. Reading up on this CRL Windshield and Repair Butyl Sealant I can’t find a tech data sheet on it, how long does it take to setup and does it tend to shrink?

DUB

The CRL does not shrink that much but it does stay somewhat flexible.

AS for the POR-15...the only way it works is if you use the MARINE CLEAN...and then the ACID ETCH like they define in their procedure. SO...depending on how much of a band-aid fix you want to do due to the car is not being taken apart. That choice is up to you....and decision much like this is what I encounter a lot.

I know what I am supposed to do...but often I am not giving the money to do it as it is needing to be done...so any repair is thus then sub-standard (in my opinion) and all I can hope for is that whatever I did.... will last.

DUB