Advice please on current thinking about sealants for handrails...

[Frank Langer]

Hi,

I have done a search on this site, but haven't found a recent post to help, so I need your best wisdom, please.

The two exterior handrails on my E30+ are mounted on six raised fibreglass mounts each, where they are thru-bolted, with the starboard one aligning with the interior handrail in the salon.

About five years ago I removed the caulking between the handrail and each mount and resealed it with Sikaflex 291, but didn't remove/rebed the handrails. It has lasted til now, but the sealant looks like it's becoming a bit chalked and slightly crumbly (UV damage??) and is letting go slightly at the handrails. To avoid any chance of leakage and to refresh, I'm planning to revarnish the handrails and reseal them.

My plan is to remove the varnish (scraper or careful sanding), cut away all of the sealant with a pocket knife or utility knife, vacuum away all residue, wipe handrails and fibreglass mounts lightly with acetone to clean, then revarnish the handrails and lastly, apply new sealant.

I have researched sealants and talked with our local chandlery, but am still undecided on which is best. I can't use butyl because I'm not actually removing/rebedding the handrails and I need to fill the approximately 3/16" gap between the handrails and fibreglass mounts. Ideally I want a sealant that will seal well, is UV resistant, won't yellow, will apply fairly neatly, won't crack, will last as long as possible and allow for removal whenever I need to redo it again.

I am considering 3M UV4000, Sikaflex 291, 3M 4200 and maybe LifeSeal/LifeCaulk (though I have heard that the latter are very gooey and hard to work with) in that order.

Does anyone have any suggestions for a better process and especially any advice on which of the above, or any other sealant, would be best. I want to stay away from Silicones, as I understand they really mess up the surface for any subsequent work; I also want to avoid the polyurethane adhesive sealants like 3M 5200 which seem to be very hard to remove later.

Thanks for any advice!

Frank

 

[tenders]

How about a photo? I can't picture how butyl won't work for this. I'd suggest removing whatever it takes to MAKE butyl work, but maybe I'm not understanding something.

 

[Christian Williams]

I would clean the old sealant first and then complete the entire varnish job so the wood is left absolutely nonporous.

Then I'd tape off the unsealed space as well as possible, use any of the products you mentioned and my finger as a smoothing device, and clean up with solvent.

Rails must be hard to get off, or of course you'd do that.

 

[Frank Langer]

Thanks for the replies so far! Tenders, I don't have any pictures to show the handrails and am not at the boat. To remove the handrails I would have to drill out the bungs and then remove the screws/bolts which have probably been in there forever and may not come out without damage to the handrails--none of that is needed because I can revarnish the handrails easily while they are on the boat, and once I seal the space between the handrail and it's fibreglass mounts there is no way for water to get in.

Christian, I agree that likely each of the sealants I listed would work, but I'm a bit of a perfectionist where my boat is concerned, so I'm wondering if any of them are much better for this application. In my current thinking, the UV protection of the 3M4000 sounds good, but it is harder to remove than Sikaflex, but this doesn't have the UV protection--on the other hand it did last about five years before beginning to degrade a bit (but I haven't tried to remove it yet!).

Thanks again for your replies! Any additional advice is welcome!

Frank

 

[celtic sea]

From my experience the life seal/caulk turns yellow and I wasn't to happy with that product. The 3M4200, or uv work great, but maybe its just me. I like the 3M products.
Good luck, I need to fix a couple of mine also.
John
Celtic Sea
E27 1973

 

[Maine Sail]

Frank,

If you want a low adhesion sealant that does well with UV then Sika 295 fits the bill. Personally if going to all that work I would remove varnish 360 degrees and re-install. Moisture gets in from open unsealed area of the wood and can "lift" the finish sooner if not sealed well..

 

[Frank Langer]

Thanks, Maine Sail. I know you're right about sealing the handrails 360 degrees with the varnish for best protection so I'll have to think about whether I have the patience and am willing to risk damaging the handrails to get them off the boat.

So far, it seems that Sikaflex 295 would be the best sealant choice, followed by 4000UV, depending on availability in our area.

Thanks again!

Frank