Originally Posted by Bren
I filled my torque mount and let it sit for 3 days. I used pl poly urethane from Home Depot. Has anyone else had melting trouble with diy poly mounts? Now I have to clean up this muck and try to salvage the mount.
Nope, takes much longer to cure. Also i have found that PL Urethane is probably not the best for mounts or moulding in general since it cures from outside in, and once the outside cures it takes much longer for the inside to fully cure due to the sealing effect. There's no catalyst for curing, as there would be with two part polyurethane, so it cures from outside in, like a cake.
3 days would have been fine only if it were submerged in water. Water speeds polyurehane up a lot. All my mounts are made out of PL. For the tranny mount what i did was make a rough mould out of tin foil, burn the rubber out with a torch (easiest way, by far, trust me). There is a supporting plate in the rubber (basically a big washer for the nut and stud that goes into the tranny, to distribute the preload over the rubber). That gets re-used, since all you are doing is replacing what was made out of rubber, with urethane. You can place it in the urethane before curing so it stays in there much like the stock mount, but i didn't. Just placed it over top of the (cured) urethane, torque down, and it hasn't given me any trouble since the day i put it in.
The passenger side hydraulic mount is the same procedure, cut the chamber seal out, empty the oil, cut out the aluminum baffling with tool of your choice. Scrub the hell out of it with any dish detergent (Sunlight preferred), dry in the oven at 250F.
Mine are fine since i let them cure fully, however you may want to learn from me and get the proper two part urethane for moulding large chunks like mounts. I think McMaster Carr sells it, and they have different durometers 60, 80, 95 i believe to choose from.