Best Bedding Sealant?

[seafox]

I was using a caulking gun today to lay a bead of sealant on an instrument panel and the disc at the end of the gun slipped down the shaft causing the shaft to plunge into the 3M 5200. What a drama. Ended up having to use a sail batton to push the remainder of the sealant out and then had to slice the tube to get at the last quarter.
The gun couldn't have broken at a worse time!

[knottybuoyz]

Originally Posted by irwinsailor

They tell me that it will be safe and i will not have any trouble.

How are they holding up Gunner? Considering doing the same for our trawler. I think I saw a pic of your windows but can't locate it.

[DeepFrz]

Seafox, I sure hope you never have to remove that instrument...

[seafox]

That's what disc grinders are for.

[Lancerbye]

Since we are into windows. What is the best sealant to use with polycarbonate windows, since I have been told I can't use Sikaflex which I normally use for everything? I have one large pilothouse side window which is UV checked I believe it is 3/8 in polycarbonate sheeting but won't be sure until I take it apart.

[irwinsailor]

My windows continue to look Great. There have been no problems and no sign of problems so far. I would use Sikaflex again.

[GordMay]

Sika makes dozens of sealant-adhesives.
Their Polyurethane-based Sikaflex 295UV and SikaPrimer 209 can be used on plastic (polycarbonate & Plexiglass-PMMA) windows.
Goto: Sika Corporation | USA

[Lancerbye]

Thanks Gord. I have used Sikaflex a lot in the past and found the biggest problem was trying to take something apart afterwards if I had used Sikaflex as a bond. I guess they have added a few more products to their line. Great stuff. Never leave home without it.

[Talbot]

If you are using it for windows, it is essential that you use the correct UV stabilised variant which is designed specifically for this purpose. Some of the others will break down quite quickly when exposed to UV.

It is highly recommended that you tape everything around where you are sticking sikka as its the very devil to remove an accidental smeer.

[Cheechako]

Also, a word of caution: I rebedded chainplates in Trinidad when it was hot and humid. Did a meticuloous job of cleaning out all the gaps etc around the chainplates and forced it full of 5200 finsihing with a wonderful smooth fillet on the outside. The next morning the gas in the 5200 had outgassed in a manner to leave little holes(bubbles) and a couple of big bubble gum bubbles also! what a disappointment. Never had that happen before, not sure if it was the humidity, heat, or both. The 5200 was put in in the afternoon....

[GordMay]

Originally Posted by Cheechako

... I rebedded chainplates in Trinidad when it was hot and humid. The next morning the gas in the 5200 had outgassed in a manner to leave little holes(bubbles) and a couple of big bubble gum bubbles also!
...not sure if it was the humidity, heat, or both. The 5200 was put in in the afternoon....

Polyurethane adhesives, like 3M “5200", are moisture cured. Moisture reacts with the urethane (isocyanate) to form a crosslinked polymer, producing a carbon dioxide by-product. This CO2 outgassing is exacerbated by application in high humidity and/or temperature conditions.

Improper application can also entrap air voids in the sealant. Always fill a prepared joint from the bottom (interior), filling the joint completely (taking care to not entrap air), and tool the joint immediately (within 5 - 10 min) after application. If required, water with small amount of detergent (<10 - 20% solution) can be used to help tool or smooth the required finish of the sealant.

See:
http://multimedia.3m.com/mws/mediawebserver?66666UuZjcFSLXTtlx&EO8TVEVuQEcuZgVs 6EVs6E666666–

http://multimedia.3m.com/mws/mediawebserver?66666UuZjcFSLXTtMXfXnXfXEVuQEcuZgVs 6EVs6E666666–

[Jim St.Pierre]

Hello Gunner, Glad you found a good sealant for your ports. I am in the process of resealing a couple of my hatches, while I am still on the hard. I have removed them and found a small crack in the gelcoat, which I will repair with "West System". The adheasive that was sealing the hatch was very hard to remove and very sticky. I have no idea what the product is. I am wondering if you could suggest a sealant for the hatch???? It is a two part system. I have a teak fram that the hatch sits on. I have removed both and cleaned the adheasive off. (about 4 hours of time) I can't believe the hatches leaked with all that adheasive on it, but they did. Thanks for any help. Jim

[ahnutts!]

I would go to the local auto glass shop and get a tube of the urethane they use for windshields. Its tough stuff and it keeps the rain out of your car.

Jerin