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Mako_Kupo's avatar
Mako_Kupo
Explorer
Sep 21, 2017

unknown gray caulk of doom

hey guys! my name is Sean. first post on this forum, and happy to be here after many recommendations. long story short, I'm rebuilding a classic 79 ford coachman Class C. the truck is in great shape, and so is the campers wood frame(mostly).

it has been decently taken care of, someone made attempted repairs that resulted in all the plywood rotting to nothing, but most of the frame remaining intact. all appliances, while being mostly replaced, still work perfectly and are original. I will be using all of the original windows, door, and exterior metal panels. they are all completely removed and in the yard.

over the last almost 40 years, the repairs appear to be done with whatever the person had on hand, or was suggested to them by somebody else and then used. the result is at least 5 different caulking being used around the entire camper. I've managed to remove most of them, the silicone is tricky but there is one that is worse.

I don't even know what it is, its a silver-gray color and extremely tough. I've tried paint thinner, water based caulk remover, and silicone remover. nothing even lays a finger on it... its like gum thats been somewhere for 100 years, its still pliable, but absolutely will not come off - period.

is the next step heat and scraping? its sort of cold out all of the time now, low 70's as I'm in CT. ill be around here a lot, and am leaving on a cross country journey soon and will be on this site the whole trip! hi! :D. thank you so much!

15 Replies

  • Wire brush on a 4" grinder. You may not to use this if you don't want to scratch the paint. It will remove it, too. Sometimes it is easier to remove to bare metal and then paint or leave bare with the sealant removed. Anything you leave on the metal will interfere with new sealant, silicone film being one of the worst.
  • Sometimes those little razor blade scraper knives work better than putty knives. Sometimes they don't. If you get it down thin enough perhaps you can remove the last little bit with sanding or scotchbrite pads or steel wool or some other similar means.
  • I've used a metal putty knife and heat gun. Warm/heat the caulking a bit, taking care not to damage surrounding materials. Stop and let the heat sink in. Repeat.

    Heat the metal putty knife and then carefully use it to scrape and peel the caulking off the surface. Be careful not to damage the surrounding materials or cut into them with the knife.

    The putty knife is more to warm and peel, not too much scraping. I recommend using nitrile gloves with a rag to wipe the caulking off your gloves as you go. Good luck!
  • plenty of that already, but it only smudges when I get it that close - and I've gotten it that close on every inch of it. all thats left is the 1mm of it that refuses to die

    ill provide pictures tomorrow!