What is elastomeric sealant?

[Rachel]

I ran across a mention of "elastomeric sealant" on the web (someone used it for sealing a nav light) and got curious about it. A bit of Googling and I'm still not sure, although I have the feeling it might be related to butyl somehow. One product link that came up was for Elastomeric Marine Sealant by Rule, stocked at Jamestown.

http://www.jamestowndistributors.com/us ... o?pid=8220

It certainly sounds like it has potential. Does anyone know more about it? Is it just butyl with another name? Does it compare to, or is it the same as, another type of caulk/sealant that we're (I'm) generally more familiar with?

Perhaps most important: Have they snuck any silicone in?

From Jamestown's page:

* Elastomeric sealant can be wet sanded and painted after curing.
* Heavy duty use above or below the waterline.
* Twists, bends, expands, compresses.
* Use elastomeric sealant adhesive to seal ports, beds hardware, and ststops leaks.
* Adheres tenaciously without primers to fiberglass, glass, all plastic.
* Cures in temperatures from -20 degrees to +120 degrees fahrenheit.

Thanks,
Rachel

[forrest]

Thats funny, I saw that stuff at my local store today and was wondering the same thing.

[Rachel]

Hi Forrest - welcome to the forum! Bellingham is a nice place :)

So that makes two of us curious...

R.

[Hirilondë]

The name just means it stretches a lot. Seems strange to me that the tab for tech info says nothing about its primary chemical make up. The add reads like its the greatest, but I will let others prove it first.

[Tim]

The funny thing about ad copy is how it makes whatever product or service always sound like the greatest. You'd think the purpose of ad copy was to sell product or something.

BTW, the only sealants I know that come in clear are silicone-based.

[Quetzalsailor]

If you Google 'elastomer' and then go to the Wikipedia definition, you'll read more than you'd want to know. A quick count shows 26 different types of elastomers encompassing nearly all the sealant types that have crossed this Forum, and most of the natural and synthetic stretchy materials we've ever heard of. DuPont, as a further example, had a whole division called 'elastomers'.

The ad copy cited is telling the buyer essentially nothing by saying 'elastomeric sealant'.

Worrisome that Tim observes that all clear sealants he knows are silicone based. I've bought what I thought was acrylic painters' caulk that went on white and cured clear-ish. I also bought some exterior quality (said so right on the tube!) goo that cured clear and was supposed to be paintable which I used for a place on Q's woodwork that needed to be perfectly watertight, clear and varnishable (the joint is imperfectly wide and deeply veed, so there's no doing it neatly). So far, so good. Normally, nothing sticks to silicone and it's devilishly hard to remove.

[Figment]

It's a space-age technology.

[bcooke]

If you Google 'elastomer' and then go to the Wikipedia definition

As an aside, I just found out that any moron can erase and re-write a Wikipedia definition. I was wondering about some info there and got to looking around and asking questions. Very little Wikipedia info is actually backed up by real facts. The articles are mostly just stories and faulty ones at that.

'Marketing' and 'Advertising' are just fancy words meaning 'To lie and deceive outrageously'. I think I read that on Wikipedia...

[feetup]

I think the time of enlightenment for me was when I spied a book on the shelf of a local book seller entitled; "How To Lie With Facts".
I suppose I was a bit innocent before that.

Tim J

[forrest]

As an aside, I just found out that any moron can erase and re-write a Wikipedia definition. I was wondering about some info there and got to looking around and asking questions. Very little Wikipedia info is actually backed up by real facts. The articles are mostly just stories and faulty ones at that.

In defense of Wikipedia, the journal "Nature" did a side by side study of it and the Encyclopedia Britannica and found they had similar error rates. I've always found it to be pretty reliable.

[bcooke]

Interesting. Their articles about Dories are pure fiction. I have been talking to a wiki moderator about bringing them up to some level of truthfulness. The Triton article used to be pretty bad but now I see it is only a bit bad.

Now I wonder about Britannca.

[John, CD28]

I used Rule's Elastomeric Sealant to bed bronze thru-hulls on an old boat once. Just a few years ago, the current owner of that boat & I pulled them back out, and the elastomeric sealant looked fine. Also, One of the guys at my club used it to seal bronze ports and removed them again years later. He also said the elastomeric sealant was in very good shape and still kept a watertight seal. He highly recommends it for bedding ports.

It goes on like clear silicone, then cures transparent and rubbery. It does have some adhesive properties, but nothing like a polyurethane. I have no idea what it's made from, but the maker's sandability claims seem to contradict the rubbery nature of this sealant.

Best,
John

[preserved_killick]

I've used LEXEL sealant around the house and it's worked great.

I just bought some to seal an acrylic sheet to a wooden hatch.
http://www.sashcosealants.com/Home_Impr ... Lexel.aspx

It's very clear, durable and you can paint it (with latex paints).

I just sealed some plastic portlights with Butyl rubber and what a pain to work with. If I thought of it prior I would have used the lexel sealant.

-jeff

[Hirilondë]

The packaging says nothing about ingredients? We don't carry the stuff at work, but I'm going to try to get the MSDS for it. I'm no chemist, but I need to know more before I try it. Having a clear that isn't silicone would be great.