Ack! Silicone Was Used on My Ports - Now What ?

[Tethys26]

I decided to take upon the mass refurbishment of my ten original Atkins & Hoyle opening ports on my 1980 Gulfstar 44 sloop (clean, anodize or powdercoat, install new windows). After removing the outer ring frame and inner opening unit, I was heartbroken to find what I *believe* is silicone, which was used to bond/seal them to the hull. It's spread liberally along the inner raw fiberglass as well as the outer gelcoat face of the hull. Everything I have read says this is bad juju.

2 questions:

1.) I am assuming it is silicone, but is there anyway to be sure?

2.) Assuming it IS, I understand it is a bear to remove and will likely combat any attempts to reseal the area, say with Sikaflex or Lifecalk. Any suggestions on how I should proceed? Should I just remove as much as possible with scraping/mineral spirits and hope for the best?

Thanks in advance!
-Lloyd

[osirissail]

No easy way - use knives, scrapers, gouges and anything else that will remove the silicon caulk. Then use sand paper to remove any microscopic residue. It is a laborious process and you need to really pay attention to getting all of the stuff.
- - Since nothing will adhere to cured silicon it is not advisable to try to use other sealants/adhesives over any residue of the silicon.

[Tethys26]

Originally Posted by osirissail

- - Since nothing will adhere to cured silicon it is not advisable to try to use other sealants/adhesives over any residue of the silicon.

So just go back to silicone? 3M 3200? Anyone have a preferred silicone?

PS: Nice boat! I always like the 53's layout.

[Ram]

I beleave Lewmar says to use silicone- would 5200 be a better choyce if the area was completly cleaned?

[Marksman]

3M 5200 is a permanent sealant and should not be used on anything you ever plan to remove again. The 3M 4000 is a much better choice for such things or Life Caulk as some folks prefer.

[James S]

Originally Posted by Ram

I beleave Lewmar says to use silicone- would 5200 be a better choyce if the area was completly cleaned?

I wouldn't use 5200 if there is ever a chance you would need to remove them....it is an adhesive.
I removed all 13 of my bronze portholes...took them completly apart, plated them and put them back together. its a huge job, the seal was particularly hard to find the right material for.
Good luck.

[cabo_sailor]

For removal I would recommend, based upon personal use, a product called Marine Debond. It will even remove 5200. Personally, I will never willingly use either silicone or 5200 on my boat. There are better products than silicone and if I need the strength of 5200 I need to do a better repair job.

For a lot of sealant jobs, particularly ports and through deck fittings I've been increasingly turning to butyl nitrate tape. A roll of about 40 ft will cost around $5 USD from an internet supplier of RV supplies. The roll I buy is about 1 in across, roughly 1/8 in thick and a light grey in color.

As to the Debond, my friend used it to remove old windows on his 28 Sabre. It took him about 20 minutes per window to get past the silicone and remove the old stuff. I've used it for portlights and deck fittings sealed with who knows what. I turn to it first before harsher methods.

Rich

[Bloodhound]

Originally Posted by cabo_sailor

For a lot of sealant jobs, particularly ports and through deck fittings I've been increasingly turning to butyl nitrate tape. A roll of about 40 ft will cost around $5 USD from an internet supplier of RV supplies. The roll I buy is about 1 in across, roughly 1/8 in thick and a light grey in color.
Rich

Yup, great stuff, cheap, and an excellent seal. Just keep the unused tape dry and cool. Most RV stores carry it

[Tethys26]

After doing some more reading, I'm thinking the Butyl looks good too. I've shot an email off to Mainesail to get his read on using it after silicone.

[skipmac]

Originally Posted by Tethys26

After doing some more reading, I'm thinking the Butyl looks good too. I've shot an email off to Mainesail to get his read on using it after silicone.

Be sure to let us know if you get any good tips. I've got the same problem on my boat.

[osirissail]

I would suggest biting the bullet and removing the old silicon mechanically. New silicon will not adhere to old cured silicon so you would have only a compression seal versus having a "bond" between the port and the hull.
- - Using T5200 or just a good silicon is really a personal choice decision. T5200 is a living bitch to remove - but - it really grabs onto the two parts and the seal is near perfect and leaks are very rare. Because boats flex like crazy when underway using anything less usually means leaks.
- - Good Sikaflex usually works second best to T5200 in my experience. But the key to not having any leaks no matter what the sealant/adhesive is a very clean surface for the sealant/adhesive to bond to. And that is really only obtained the hard way.

[svHyLyte]

There is a product by the name De-Solv-It that will removed cured silicon. The trick is to be able to saok the effected area for several hours after which the stuff does come off very easily. I used it to remove cured silicon from some older hatch lites and it did work as advertised.

FWIW...

[Tingum]

Just be thankful that they were not installed with 5200!

[svtrio]

The link below is to a Q&A page for GE silicone. Interesting bits of info, including suggestions for removing silicone.

<http://www.caulkyourhome.com/frequently-asked-questions.php#trbl_3>

BTW, most silicones have acid in them, which can be bad for a variety of surfaces including metals (especially aluminium), but the GE Silicone II is acid free.

[steve_hendry]

I've been replacing the plastic opening ports on my boat with NFM ports (5 of 6 done). ACE hardware has a silicone caulk remover that does work. You need to mechanically scrape as much as you can, then it will take 2 or more applications of the caulk remover, followed by acetone for final clean-up.

I'm using LifeSeal (silicone/urethane) for the new ports.