Re: [Amel Yacht Owners] Re: re caulking of stanchion base
Bill Kinney,toggle quoted messageShow quoted text
I was originally thinking of using a non acid based silicone caulking for bedding my stanchions but I think that you may have hit on the perfect solution using the Butyl tape to provide the required sealing. The caulking seal would have to rely on a good bond whereas the butyl should produce a good seal simply from compression and chamfering the top of the hole will increase the reliability of a compression seal. While the butyl might not attach well to the fibreglass if some Tef-Gel is present, it will be well adhered to the inside of the stanchion base so should not try to crawl out. You can also come back and gently tighten the bolts at a later time with Butyl which would destroy the bond and seal of a caulk. The Butyl should reseal to the bolt in response the increased compression. Finally, since these bolts really should be replaced and resealed as a part of a maintenance schedule the butyl is going to be easier to clean up. I really really like your plan and will be packing some Butyl into my luggage!
Do the holes tapped into the embedded steel bottom or pass completely through the steel? I am thinking that if they pass thru that we can afford to be more generous with the Tef-gel since it will not be forced out of the hole to the surface. If the holes bottom, your idea of using a bolt to apply the Tef Gel to the female threads sounds like an excellent way of applying the optimal amount of product.
I also sometimes chamfer holes to provide a clean surface for caulking to bond to and I do think that it improves the seal. I am sure that you will be careful to not cut away too much material but I have seen on a number of boats where the chamfering has extended pretty deep into fibreglass which can be a bad thing structurally since the shear strength is going to be reduced.