Rebedding jack mounting plates

I don't like butyl tape in general, and in particular I sure don't like it for this application. It is thick and greasy and does not harden for a very long time. Those plates are loaded in shear with self tapping screws into a wood backer. They need all the help they can get.

The butyl will ooze out of the joint for a long time (like years or anytime it gets warm). That is a mere annoyance, but it lubricates the joint like grease, exactly what you do not want in a shear connection with dodgy fasteners. As the butyl oozes from the joint, the screw tension relaxes. You can go tighten them again, but the process repeats.

I would clean everything properly and use 4000 UV, Sikaflex, or perhaps even 5200 on them. The bulletproof way to do this is liberal use of the PU or PE sealant, do not coat the fasteners, put them in just snug and wait for the sealant to set. After it has gelled, pull the screws out and coat them with the same, then back in drawn up. The reason for this is you want a bond line of sealant a minimum thickness to do it's job, not completely squeezed out by fastener tension, then you want the screws to be sealed and put a bit of compression on the set sealant. This installation will be significantly stronger and watertight far longer than butyl tape (like 20 years would not be an unreasonable expectation). If you have to get them off someday for some reason, it will be some work but it is still possible.

Last wwek I removed one of my jacks it had butyl tape under it and it was still pliable after 16 years. I remounted the jack with new tape, screwed it down, let it ooze. I then cut that off and applied a new product recommended by a service tech, Excel, it's clear non silicon and very easy to work with.

I presume they were caulked around the edges and holes for water infiltration.

My jack brackets were not "bedded" at all. The only thing holding them was the screws and caulking. They popped right off once the screws were removed.

One thing I did was epoxy dowels into the screw holes and redrill them when I went to remount the jack bracket. Then I used Dicor as I inserted the screws, then Dicor around the edges of the bracket.

NRALIFR wrote:
Well, I’ll say this for it: it sure looks nice without the butyl goo oozing out from under it, and it will stay that way. I’m not really a fan of butyl tape under something that gets as much pressure put on it as a jack mounting plate does. OSI Quad and Sikaflex are both polyurethane sealants, and good quality products. They cure to a rubbery consistency that allows some movement without cracking.

I’m not really too concerned about removing it either. The chances are slim I’ll ever need to, but if I do I’m sure I can do it. Might not be easy, but I’ll get it off.

:):)

I suppose of it is sealed right, there should never be a reason to remove it.

Well, I’ll say this for it: it sure looks nice without the butyl goo oozing out from under it, and it will stay that way. I’m not really a fan of butyl tape under something that gets as much pressure put on it as a jack mounting plate does. OSI Quad and Sikaflex are both polyurethane sealants, and good quality products. They cure to a rubbery consistency that allows some movement without cracking.

I’m not really too concerned about removing it either. The chances are slim I’ll ever need to, but if I do I’m sure I can do it. Might not be easy, but I’ll get it off.

:):)

NRALIFR wrote:
I recently completed a Winter TC Repair Project that involved removing one of the rear jack plates to fix some water damage, and when I reinstalled the plate I bedded it in OSI Quad urethane caulk. The same caulk I used on all the edges and seams. It’s a little difficult to work with because it’s solvent cleanup, but it has great adhesion. Once it’s cured, I think you could remove the screws and bolts, and it would still hold the camper up.

I hope I never have to remove the jack plate!

:):)

Bold sir. Glue it on there and go. I love the confidence.

Talk about removing the bolts from the jacks. Bob the former owner of Snowriver TC’s used Sikaflex on his campers and he would demonstrate how the Silkaflex would seal so good that you could do just that, remove the jack bolts and the jacks held up the camper. I would use butyl tape, tighten the bolts, let the butyl squeeze out and seal with ProFlex RV sealant. You can model the ProFlex with your finger dipped in soapy water.

NRALIFR wrote:
Once it’s cured, I think you could remove the screws and bolts, and it would still hold the camper up.

I hope I never have to remove the jack plate!

:):)

That might be why they recommend butyl tape. :D

I recently completed a Winter TC Repair Project that involved removing one of the rear jack plates to fix some water damage, and when I reinstalled the plate I bedded it in OSI Quad urethane caulk. The same caulk I used on all the edges and seams. It’s a little difficult to work with because it’s solvent cleanup, but it has great adhesion. Once it’s cured, I think you could remove the screws and bolts, and it would still hold the camper up.

I hope I never have to remove the jack plate!

:):)

My guess is butyl tape.