POR-15Patch - Black 4 oz - Filler & Seam Sealer | Ultimate Filler Adhesive | Patches Holes, Cracks in Steel, Wood, and Some Plastics | Strengthen Weakened Metal

I have an old dodge that came with the rust feature. I needed to patch a hole in the floorboard but didn't want to cut and weld or commit that much time to an old work truck. So, I decided to give this recommend stuff a try. The hole was about golf ball size so I used fiberglass cloth as the reinforcement. The first layer went on easy and it requires less than you think. The consistancy is a bit thinner than gasket maker. After drying, it was hard but still flexible like thin plastic. So, I did two more layers fiberglass layers on top and one on bottom. Now, it's hard as a rock. Could I have used regular fiberglass resin and got the same result. Maybe. But I think I would have needed to sand down to metal as resin needs a clean surface to bond well. But then again, this stuff might not have bonded well but it seems like it did. I feathered it out double of the hole with only a wire wheel and acetone prep and it looks and feels nice. I poked different areas and it only sounded hollow in a thicker area where I put the sheet on the underside and might have not had enough por-15 squished in. It states it needs 96 hours to fully cure if thick but just sitting overnight in a hot garage seems to be enough for me. It might harden more which is fine but it's hard now. I'm going to test to see if it's water proof today as I was getting water in my floorboard. I'll update if it isn't.

I have a rough car that I could not justify cutting out the rusted cowl (metal area below your windshield where wipers mount) in. I determined the leaks into the interior were from other areas of the cowl where the panels mate to the firewall so after grinding out the 40 year old caulking and hitting with a wire wheel I used the POR-15 semi gloss black paint and a couple days later used the POR patch. It has a heavy viscosity that flowed and simulated the factory caulking perfectly on my A-body GM car and I have seen zero leaks and don't ever expect to. Now back to the heavily rusted cowl that i decided to experiment with the POR patch on. It had multiple totally rusted out areas but as the affected areas would not generate additional interior leaks and the entire rusted out area was covered by a wide stainless steel factory trim piece I decided to save a bunch of money and avoid needless delays waiting on a bodyshop to drag me out on. I ordered two tubes of this patch which was enough to seal all the cowl seams mentioned earlier and also enough to patch the swiss cheesed cowl AFTER my additional mods to help bridge the gaps and reduce the thickness of the POR patch needed. First I bought a cheap sponge and cut into smaller strips and soaked that in my POR-15 paint and I soaked the front of the cowl area as well as the underside of the cowl to stop the rust dead in it's tracks. Then I ordered a 1'x1' sheet of very fine stainless 316 grade stainless steel. Measured out each rusted section, found perimeter metal that was still strong and drilled the cowl there and through the metal screw I supported underneath with wooden paint stirring sticks so I didn't ventilate my hand lol. Then I used stainless steel 1/8" diameter pop rivets (recessed them down flush with ballpeen hammer)to secure the screen to the cowl. It's hard to support sagging areas of the mesh screen from behind in the tight cowl area so I crammed foam or rags temporarily behind the screen to force it higher to limit the amount of POR patch needed. Due to the thick viscosity and the very tight screen mesh(#40 .010) I did not have any bleed through the screen to the temporary support materials. I used the POR patch straight out of the tube without the reducing nozzle since I had large areas to cover and then I skimmed the excess off with a razor blade and used what was left on the blade for pin hole areas which it filled without a second thought.I am sure many folks will disapprove of this method verses a very expensive cowl replacement but I have used POR products for decades and swear by all of them. The seams are all sealed,the rotted cowl is one solid piece again and my interior is dry. I have much more time than money these days and as always POR products did the job without breaking a sweat. Just get some heavy mil gloves unless you like stained skin for weeks and there thinner/cleaner did a great job of removing both products from my arms or areas I did not want it on the car.Highly recommended product! : )

I have used the POR 15 in brush form. This now in tubes, I am restoring a 68 Camaro and after sanding my cowl down to bare metal I found a few small holes below the windshield. I used the tube sparingly to fill a couple holes. 24 hours later I sanded down the spots and painted primer over them. Good as new. Great product just don’t get it on your hands, it won’t come off.

The price is a little higher. If they can make smaller tubes that would be great for small jobs. I had little rust coming in my 2007 Civic near the rear wheel. I covered the area with this product. after a few hours, it was rock solid. Hopefully, rust will quarantine inside and will not bother me at least for a few years. Will update you in the future with what happened.