[Rhodes22-list] Sealing hull to deck gaps

[Mark Whipple]

From Practical Sailor:

Silicone caulk is notorious for wreaking havoc with the adhesion of
sealants and paint. In fact, you will probably find that new silicone
bedding does not bond well to surfaces that have been supposedly scrubbed
clean. The trouble is that old silicone can be deeply embedded in the pores
of gelcoat and wood, invisible to the naked eye.

https://www.practical-sailor.com/boat-maintenance/ps-tests-adhesive-removers

and

Many companies, including Pettit—who have launched a new line of caulks,
<https://pettitpaint.com/products/sealants-adhesives/>offer new
UV-resistant and paintable polyether blends that can be used in lieu of
silicone, which has a reputation of leaving behind invisible residue that
can interfere with the adhesion of subsequent coatings of paint or varnish
on the bedded fitting, or even on the adjacent surfaces. If you have to
remove silicone or remove stubbornly adhered polyurethane caulk like 3M
5200, check out our Practical Sailor’s test of adhesive removers
<https://www.practical-sailor.com/boat-maintenance/ps-tests-adhesive-removers>
.

https://www.practical-sailor.com/blog/the-right-caulk-for-your-boat

I can confirm from experience that it can be nearly impossible to get
anything to seal to surfaces that were previously exposed to silicone
caulk. I've had to use a digester solution to remove the silicone from the
gelcoat.

Mark

Boston, MA

2000 R22 *Luna Mia*


On Wed, Jun 29, 2022 at 12:07 PM Michael McKay <mm.bizlist1 at gmail.com>
wrote:

> I’ve found that there are visible gaps in the hull to deck joint of my
> boat, which allow some water to intrude when the boat heels a lot.   My
> mechanic suggested using silicone caulking to seal these areas but I’ve
> frequently read that silicone should be avoided except for things like port
> lights and hatches.   Do you have any advice or experience with this issue?
>
> Thanks,
>
> Michael McKay
> s/v Liber 2006/2018
>
> Sent from my iPhone