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I “discovered” a new sealant - polyether

Jun 14, 2010
912
Quorning Dragonfly 1200 home
I was doing a solar panel project last weekend and at 5:00pm on Saturday realized I didn’t have usable sealant aboard (my 4200 had cured in the tube). At the time and place, my best bet was a nearby Home Depot, and took off in search of....
The HD had 5200 in large tubes, but I’m not a fan of 5200 for various reasons. Right next to that they had PL Marine Adhesive Sealant. http://www.loctiteproducts.com/en/products/build/sealants/loctite_pl_marinefastcureadhesivesealant.html
“Loctite PL Marine Fast Cure Adhesive Sealant is a fast setting, moisture cure polyether adhesive sealant which delivers strong bonds while forming a watertight, flexible seal above or below the waterline once cured. Free of solvents, phthalates and isocyanates, it will not shrink when cured, discolor from UV exposure, or bubble on damp surfaces. Once cured, it withstands both saltwater and freshwater environments.
  • Cures in 24 hours
  • Ideal for marine areas and conditions
  • Withstands salt water & fresh water
  • Fast cure
  • Water tight
  • Above or below waterline once cured
  • Stong bond
  • Permanently Flexible
  • Paintable
  • Won't shrink or discolor from UV exposure”
I tried it, and I found it very easy to work with. Easy to control the bead, without pulling out into long strings as you withdraw the nozzle from the work piece. I misted it with fresh water before leaving, and next morning it was skinned over and dry to the touch. This is my new go-to replacement for 4200.
(Also, it is about 30% less expensive than the 3M alternatives).
 
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Jul 13, 2004
51
-Manta Catamaran -Manta 40 Mystic, CT
I've been using this for years. Locktite used to also make a polyurethane, but I can't seem to find it anymore. The price of it has also doubled in the past 2yrs. When it first hit the market, it was under $5. 3M used to make a polyether - it was called "101", and I liked that stuff, but they pulled it off the market several years ago for some reason. Outside the US, one can find a 3M polyether in hardware stores that seems to be the same thing, only inexpensive.

Mark
 
Jun 14, 2010
912
Quorning Dragonfly 1200 home
Interestingly, after my initial post above -- I searched for polyether sealant and one of the hits was 3M 4000UV. Perhaps that's 101 rebranded?

PS - @colemj Good to hear from you, Mark. Are you back north in our area?
 
Last edited:
Jul 13, 2004
51
-Manta Catamaran -Manta 40 Mystic, CT
I also found the Locktite polyurethane I though went missing. It used to be called PL40 or something like that, now it is called "door and window sealant", or similar. I've had poor luck with 4000UV in the past, but never with 101. They could be the same, and my applications different.

We are in Georgia. Bought a new boat (Dolphin 460) and are busy with a refit.

Mark
 

Maine Sail

Moderator
Feb 6, 1998
11,034
Canadian Sailcraft 36T Casco Bay, ME
Interestingly, after my initial post above -- I searched for polyether sealant and one of the hits was 3M 4000UV. Perhaps that's 101 rebranded?

PS - @colemj Good to hear from you, Mark. Are you back north in our area?
Yes UV 4000 is a polyether but polyether and polysulfide are two entirely different products. 3M 101 was an excellent polysulfide, I liked it much better than the Boatlife polysulfide. Unfortunately 3M discontinued 3M 101..
 
Nov 26, 2008
1,879
Endeavour 42 Cruisin
Since both 3m 4000 and the loctite are both polyether, will they both harden in the tube a few days after opening?

I have had excellent results keeping opened tubes of 4000 and 5200 in the freezer for extended periods. I always use a fresh tube below waterline but older opened tubes of the 4000 have worked great.
 
Mar 26, 2011
2,381
Corsair F-24 MK I Deale, MD
Lockt
I also found the Locktite polyurethane I though went missing. It used to be called PL40 or something like that, now it is called "door and window sealant", or similar. I've had poor luck with 4000UV in the past, but never with 101. They could be the same, and my applications different.

We are in Georgia. Bought a new boat (Dolphin 460) and are busy with a refit.

Mark
Lockite PL S40 (white) and PL S30 (black). Yes, they say "door and window" and "roof and flashing" respectively, but they are the same product. They are very much like 3M 4200, but more prone to yellowing and mildew. That said, the mechanical durability on boats and on test panels is virtually identical. I've been using them for about 15 years. At the very least, it should have some uses around the house!

http://sail-delmarva.blogspot.com/2017/05/100-best-buys-chapter-2.html

The PL polyurethances also bond better to low energy (polyethylene etc.) plastics considerably better than 3M. In this case I used PL S30 to rebuild a kayak skeg, laminating it with Sunbrella. Tough and flexible. That was a year ago, and the only damage is a little ground off the edge.
 
Jul 13, 2004
51
-Manta Catamaran -Manta 40 Mystic, CT
Yes UV 4000 is a polyether but polyether and polysulfide are two entirely different products. 3M 101 was an excellent polysulfide, I liked it much better than the Boatlife polysulfide. Unfortunately 3M discontinued 3M 101..
Doh! You're right! 101 was a polysulfide. I liked it because it never yellowed, where Boatlife has always yellowed and flaked on me no matter what it says on the tube.

Outside the US, we often find a 3M polyether, and I was confusing that with 101.

Mark
 
Apr 16, 2017
629
Federation NCC-1701 Riverside
Appears to work on "plastic". Ill bite, in the middle of a few projects where ill test it out.

Any issues with surface prep after its been removed, e.i., anything like silicone contamination?
 
Jun 5, 2010
989
Hunter 25 Burlington NJ
I make it a point to not shop for boating products, especially for structural applications, at HoDePo. Now if you'd said that Defender or APS carried it, I'd have checked it out. :dancing:
 
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