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

[Tethys26]

Thanks for all the advice on removal products. I'll try anything!

As to the butyl, since the Atkins and Hoyle ports are not through bolted (they screw into the coach roof independently), Mainesail recommended NOT going with Butyl. It sounds like it's too hard to get good compression to form a tight seal. His recommendation was Sika 295. I'll keep everyone posted.

[NCountry]

I've had really good luck with the 3m 4000 UV.... it's worked great on hatches, port lights and a number of other sealing jobs. One of my hatches had been "patched" with silicone. Thank goodness it was just the aluminum frame and part of the Lexan that had the stuff on it.

[MarkSF]

I found this on marine sealant selection :

What Sealant Do You Need? by Don Casey

As long as the parts are above the waterline, and the sealant is maintained under mechanical compression, silicone is actually OK it seems.

[Jim Cate]

We are constantly bombarded with the opinion that once Silicone is used that there is no possible means of bonding the surface later on. The above postings suggest that one can remove the cured silicone with various proprietary products.

My question is whether the products leave a clean enough surface (and substrate) to allow effective bonding. In other threads here on CF we've been told that the oils (?) from the silicone penetrate into the substrate and then leach out later, destroying any future bond. This has always seemed doubtful to me, but that's not substantiated by data. It seems like some one with adequate space and time could do an experiment to validate the claims of the cleaners, or to show that once applied, silicones really do stuff up future bonding. NOthing too elaborate, just taking some scrap FRP material, applying silicone in several areas, removing it by various methods (as recommended in above postings) and then attempting to bond something to the cleaned areas.

I'm not in a position to do so at this time, but maybe there is some other curious CFer out there who would be... any takers? It would be a benefit to us all!

Cheers,

Jim

[steve_hendry]

The 5 NFM ports I've installed are not leaking. They've been only subjected to rain, not waves so far.

[DeepFrz]

Be careful that you don't go sanding the area until you are sure that you have all the silicone removed or it will just get embedded in the gelcoat and fiberglass. Using 5200 to seal ports is foolish in my opinion. 5200 is an adhesive and not a caulking/sealing compound. And with alternative sealants that were made specifically for sealing windows in high rise buildings why would one want to use an adhesive instead.

[MarkSF]

Originally Posted by Jim Cate

We are constantly bombarded with the opinion that once Silicone is used that there is no possible means of bonding the surface later on. The above postings suggest that one can remove the cured silicone with various proprietary products.

My question is whether the products leave a clean enough surface (and substrate) to allow effective bonding. In other threads here on CF we've been told that the oils (?) from the silicone penetrate into the substrate and then leach out later, destroying any future bond. This has always seemed doubtful to me, but that's not substantiated by data. It seems like some one with adequate space and time could do an experiment to validate the claims of the cleaners, or to show that once applied, silicones really do stuff up future bonding. NOthing too elaborate, just taking some scrap FRP material, applying silicone in several areas, removing it by various methods (as recommended in above postings) and then attempting to bond something to the cleaned areas.

I'm not in a position to do so at this time, but maybe there is some other curious CFer out there who would be... any takers? It would be a benefit to us all!

Cheers,

Jim

The point is that, according to that guide, if the sealant is under compression and above the waterline, silicone sealant is fine. You don't NEED adhesion, as the sealant is working as a gasket material. So just scrape off the excess old sealant, put some new in there, job done.

[Tethys26]

Originally Posted by MarkSF

The point is that, according to that guide, if the sealant is under compression and above the waterline, silicone sealant is fine. You don't NEED adhesion, as the sealant is working as a gasket material. So just scrape off the excess old sealant, put some new in there, job done.

Ahh, that makes sense. So the alarming part of going over an area that previously used silicone is just the lack of a good BOND, ie mechanical adhesion. But you're saying the SEALING properties of any of the previously discussed non-silicone (or silicone even) products should still remain intact, given a reasonably clean surface?

[Capitain Mike]

Originally Posted by 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

Hi Rich where can I get the Marine Debond I can't find it anywhere I have found it as Marine Formula by Debond) but get no reply to my email. Do they still exist.

[minaret]

Originally Posted by Capitain Mike

Hi Rich where can I get the Marine Debond I can't find it anywhere I have found it as Marine Formula by Debond) but get no reply to my email. Do they still exist.

Here's where we get ours...

Search Results

[Capitain Mike]

Originally Posted by minaret

Here's where we get ours...

Search Results

Hi Minaret,
Thanks for the link. While looking for it I found that the company Debond 2000 was filed for closure on 12/3/1998

DEBOND 2000 - Reviews & Brand Information - DEBOND 2000, INC. TEQUESTA , - Serial Number: 75599245 are they still in existance under a different name?
do you know if they are now using a different name? I tried your link and saw it on the site I will try to get some and see what happens

[Capitain Mike]

Originally Posted by Capitain Mike

Hi Minaret,
Thanks for the link. While looking for it I found that the company Debond 2000 was filed for closure on 12/3/1998

DEBOND 2000 - Reviews & Brand Information - DEBOND 2000, INC. TEQUESTA , - Serial Number: 75599245 are they still in existance under a different name?
do you know if they are now using a different name? I tried your link and saw it on the site I will try to get some and see what happens

The purchase was completed online it did not say out of stock so I will just have to wait and see.
Thanks for the Tip

[minaret]

Np. It should be in stock, they sell lots.

[Cheechako]

the one thing about a sealant as opposed to tape is that it flows to seal the whole area as you tighten the hatch. How do you keep the screws from leaking with butyl tape? just curioius.... I'm one of those 5200 lovers and just plan to do it once. I have had to remove things before and usually it's doable. it is wierd how easy it comes off some things and how tenacious it is on others... go figure.

[Capitain Mike]

Originally Posted by Cheechako

the one thing about a sealant as opposed to tape is that it flows to seal the whole area as you tighten the hatch. How do you keep the screws from leaking with butyl tape? just curioius.... I'm one of those 5200 lovers and just plan to do it once. I have had to remove things before and usually it's doable. it is wierd how easy it comes off some things and how tenacious it is on others... go figure.

Countersink the holes in the GRP.
Insert the bolts through the holes in the hardware.
On the side of the hardware that the bolts project through.
Make a cone around the bolt against the fitting.
The point of the cone faces towards tne end of the threaded section on the bolt. inset the bolt into the fixing hole and the cone of the butyl fits into the countersunk section of the hole. Not a good picture but you get the idea?