Remove and Replacing the Deck Caulk.

[Billy V]

The Caulk Seams on the Deck of my 07- 2310 have gotten ratty after many seasons of fishing/washing.

Its time to remove, clean, and replace what appears to be silicone caulk use from the factory. I am able to dig out most of it with a scraper - but was wondering what to use for the last bits of silicone.

Is Mineral Spirits the best way to go here ?

-Also - before I go and replace this deck caulk with a Silicone - is there a better product choice for Caulking Deck Seams - or is 3M Marine Grade Silicone Sealant the correct product for this job.

Thanks
Bill

 

[fisheron]

I have some thoughts on the subject.

Silicone is cheap,easy to use,and seals for a few years. Having owned boats for 30+ years I have come to the conclusion that silicone sealants will fail over time and the resulting water intrusion can cause big problems. The 91 project parker I am restoring is a typical example. Every one of the hatches and deckplates was totally separated from the silicone caulk used to seal it. This allowed lots of water to enter the deck plywoods exposed edge and rot the floor surrounding the hatches. Now I bought this boat knowing the deck was shot. But how many other boat owners wrongly assume those hatches are bonded and all is well? Most, I believe.

3m 5200 is a fantastic permanent sealant. It is not too easy to work with but the bond has exceptional strength. So strong that I have ripped the gel coat right off when trying to remove a fixture sealed with it one time. If the joint is exposed be sure to use one made for UV exposure.

Chances are the joints you are talking about are less critical than deck hatches. I have heard good things about silkaflex's you should check them out. Silicones will work but just be ready to redo them in a few years.

 

[Billy V]

Today I spent about 3 hours digging out about 1/3 of the job.
After digging out the main portion of silicone, I would then soak a rag in Mineral Spirits and push it down into the seam with a puddy knife and let it sit for 5 minutes to soften the remaining layer.

After 5 minutes its back to scraping /soaking / scraping /vacuuming - until the fine layer is gone.

Its a tedious job and once I am silicone free - I want to stay that way.

-I am considering using the 3M 4000 UV. I will also check out Silkaflex.

I have used it in the past to seal around my bait tank, and also to install my transducer. I wish they had a slow cure version that offered more working time.

I am still open to suggestions from someone in the know.

Thanks
Bill

 

[jeffnick]

To remove old silicone I use a brass wheel on a Dremel.

This will leave a dark mark on the gelcoat which can be easily removed with acetone.

http://72land-n-sea.blogspot.com/2011/0 ... -5200.html

 

[TWOBOATER]

yeah, stay away from straight silicone. I have used =Sika-Flex with good result and also Dow 795 Sealant. it sticks really well and clean-up is very easy. Also good UV resistance.

 

[fisheron]

I plan to try my Rockwell sonicrafter on seams next time. They make a flexible scraper blade for it that's worth a try.

Small stainless wire brush may be good for the left over crumbs.

 

[Billy V]

Here is an update on removal:

One of the guys on my dock is an Auto Glazer- been doing it for 30 years - He installs lots of windshields.

He gave me a can of Quick Release Agent, a combination of mineral spirits and isopropyl alcohol.
-Says to spray it on and wait a couple of minutes and it will break the bond completely.

It works like magic. One minute after spraying it on the deck joint I saw the sides of the silicone ruffle, ran the scraper over it and it came completely out. No little pieces left - complete removal.

Nothing left to do but wipe it all down with acetone and re-calk. I am going with the 3M 4000 UV - mostly because I can't find something that states UV resistance.

 

[warthog5]

I am considering using the 3M 4000 UV

That's the Only product I'd use on it... It is designed for that purpose and it does Not Yellow.

Differently NOT 5200... The most used and abused product out there. There is only one place I use it. Engine bracket installs.

I don't even use it for thruhull installs. I use 4200 for that.