Adhesive for new Mast Step

Mar 31, 2019
64
Catalina 22 12640 Rose City Yacht Club
Hi all,

For my 1984 original design C22, I purchased the improved mast step and halyard plate from Catalina Direct, along with their mast step mounting kit. The mounting kit comes with 3M 5200. It's my understanding the 5200 is, effectively, permanent and impossible to remove. (Correct me if this assumption is wrong.)

In this situation, is water intrusion prevention really the intended use of the 5200? If so, wouldn't 4200 work? Or filling the holes with epoxy and re-drilling them? Butyl tape?

To ask another way, is the lag bolt into the compression post, along with the additional screw+nut through-deck, sufficient for keeping the mast step attached to the boat? Or is 5200 needed to provide additional bonding strength here?

Thanks!

Andre
 
Last edited:
Jan 1, 2006
7,040
Slickcraft 26 Sailfish
5200 should be considered permanent. I was once trying to remove a plywood access hole cover that was adhered with it. The plywood glue failed before the 5200. There is a solvent for it but I wouldn't count on that. I think a mast step should be removable. I guess CD doesn't. Since the mast plate is predominately under compression I think the lag bolts would provide enough stabilization to sail and probably drop the mast if you have a tabernacle. 4200 is a very good adhesive and I think a good choice to add suspenders to the belt in that system yet retain the option of removing it if, for instance, you suspected water intrusion or had a leak into the cabin.
 
Jun 25, 2004
1,108
Corsair F24 Mk1 003 San Francisco Bay, CA
You are thinking clearly, IMO.

If it’s not solid glass under the mast, You should Drill to remove the core and fill with epoxy to seal the core.
Yes, it would be a bad idea to install the step with 5200! Then use something other than 5200 or silicone as a sealant.

4200 or Sikaflex 291 LOT or BedIT Butyl tape would be suitable. I’ve used both 291 and BedIT for this job on different boats. While I love butyl tape for most hardware to deck caulking, it will ooze out forever from under the mast step. I prefer 291 for this job because it doesn’t ooze out and make a mess and you really don’t need the extreme elongation properties that good Butyl like BedIT offers you.

Judy B
 

Grotto

.
Feb 18, 2018
273
Catalina 22 Wilmington
I just did this! Redrilled mast step and potted with unthickened epoxy. I used a dremmel to clean out any rot after drilling out the hole, sealed the underside of the hole with duct tap, the very slowly poured the epoxy. sitting over the holes and adding a drop or two to each time the epoxy settles and creeps int crevices is not for the impatient. I used butyl to seal, easy to work with easy to clean up the squished excess. I also potted the compression post as it showed some moisture in the lag screw hole. Coolest part was I had 2, 1/2 inch port lights when the epoxy set. Unfortunately they are gone forever with the mast step back in place.
 
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Mar 31, 2019
64
Catalina 22 12640 Rose City Yacht Club
I just did this! Redrilled mast step and potted with unthickened epoxy. I used a dremmel to clean out any rot after drilling out the hole, sealed the underside of the hole with duct tap, the very slowly poured the epoxy. sitting over the holes and adding a drop or two to each time the epoxy settles and creeps int crevices is not for the impatient. I used butyl to seal, easy to work with easy to clean up the squished excess. I also potted the compression post as it showed some moisture in the lag screw hole. Coolest part was I had 2, 1/2 inch port lights when the epoxy set. Unfortunately they are gone forever with the mast step back in place.
Amazing - thanks for the specific guidance, and thanks everyone else above who replied with suggestions, too.

I'm going to go with Grotto's solution of epoxy + butyl since it seems like a solid solution, and I have all the materials on hand already. Will post back with results, though it will have to be when the weather is warmer in a couple months.

Best,
Andre
 
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