A 4×8 sheet of a cement backing board covered with a mortar compound used to embed the covering of white quartz marble chips screwed into brick back sometime in 60s or 70s. One heavy dog. This 4×8 sheet was caulked to an adjoining piece of the same to cover the seam. Owner wants the brick exposed so take off the sheet. I finally remove the last screw and am expecting the sheet to drop the 2inches it is above the sidewalk. Nothing happens. Ah, a hidden screw. Where is it? I pry the side of the 4×8 to see where the connection is and the thing pulls from the brick. What? The rubber based caulk is still pliable and the whole 4×8 sheet swings open like a door on a hinge. I try to move it up and down. No movement. Open it all the way flush to the wall to try to crack the seam. Nothing. I get the ladder and with the sheet perpendicular to the wall I apply about half my weight to the top corner before she starts to give. Never seen such a thing. Sure wish I knew what caulk those guys used.
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If it's brown it's likely 2 part polysulfide.
it's a rubbery texture. white that looks like it came from a tube that wasnt smoothed over.
No idea if it's white.
I've a 2 part polysulfide sample that's been on a test roof or in my desk drawer for over 30 years, still like day one. Used to seal aircraft fuel tanks.
Rez-- Geocel (Pro-Flex) Don't know if this is it but this caulk is the olny stuff I will use on exterior work. It's great caulk. You need to use paint thinner for smoothing and clean up as it is not water base.
cliff- were they making it 30 years ago?
I first saw it in the early eighty's. It could have been around a few years earlier in some areas. Good stuff. Butyl-Flex is probably waht you are looking at. It came in several colors and dates back about 30 years.
Try tooling the Geocel (Pro-Flex) and the newer polyurethanes with a mixture of soapy (Dawn dish soap) and water. I use a sponge paint brush. Dip the foan brush in the soapy water and slick the caulk joint with it.
Dave
Might have been manufactured by Tremco, as they said in their blurbs, it has "tenacious" adhesion...
While we're talking exterior caulk...... I have a concrete front porch, floated over a crawlspace, with a brick facade. Rather than hang the slab over the brick, I brought the brick up flush with the top edge of the slab (I didn't want the slab showing from the road). Of course now there is a small crack between the mortar and and slab that I need to caulk to keep water out (if it freezes it'll pop the brick right off).
What would you recommend for this? I don't want the caulk to be noticeable. In fact, I'd really like for it to look like a mortar joint.
Sonolast makes a good "limestone" colored urethane caulk. Vulkem and Dimonic (from Tremco I think) do also. From what you describe, these are what I would use. If a larger gap, use foam backer rod b/4 caulking. This stuff will last. A bit harder tooling wise but worth the effort.__________________________________________
Remodeling Contractor just outside the Glass City.
I would be hard pressed to use anything but polyurethane on exterior work, with the exception of glass and expansion joints.
Ken Hill
I'm a slob when it comes to tooling the elastomerics, polyurethanes, any of the real good, real sticky ones. So, for small gaps like yours, I've been using DAP concrete and mortar filler. Blends in great.
Rez--Don,t know when they started making it but it's great caulk. It has great adhesion and pliability. I've removed it on jobs that I did 10-15yrs. ago and when I pulled the siding off it was still bonded to both surfaces and "rubbery".
I'm going to try it. Thanks