Through hull bedding compound

George ( C&C 40 ) · Post by **George ( C&C 40 )** » Fri Mar 23, 2007 9:14 pm

Hi All,

I finally got around to getting all 7 new through hulls ( 2 new and 5 replacement ) dry fit and ready to be installed. I know there was some discussion on various types of bedding compounds for through-hulls. I've always used 5200 for this job but I believe there were some comments to the effect that 101 might be a better choice on an installation in solid fibergalss where the seacock is through-bolted in addition to the through-hull fitting itself. Did we ever come up with a consensus on this topic? All my fittings are solid bronze.

George

P.S. I have lots of 5200, 4200, and 101 on hand so I'm ready for anything.

Hirilondë · Post by **Hirilondë** » Fri Mar 23, 2007 10:01 pm

I don't use 3M 5200 or Sikaflex 292 for anything that I might ever want to remove unless there is absolutely no other way to adhere it. This is particularly so for anything that is mechanically fastened well. I just see no point in it. This being said.......

101, Sikaflex 291 and Lifecaulk are all good choices for bedding. There is still debate as to whether they are good for polycarbonate and acrylic, but for through hulls I would feel comfortable using any of them.

4200 is somewhere in between in regards to adhesive properties.

(flips coin.......it comes up tails) (shrug)

bcooke · Post by **bcooke** » Fri Mar 23, 2007 10:14 pm

Did we ever come up with a consensus on this topic?

Not even close.

The same topic keeps coming up year after year and if anything, MORE options and opinions keep popping up every time. The funny thing is, I believe almost every suggestion would work just fine. Like so many things there is no one perfect choice.

-Britton

George ( C&C 40 ) · Post by **George ( C&C 40 )** » Fri Mar 23, 2007 10:20 pm

Thanks guys,

We don't have to drag this out. Since I did the full work up on the through hulls -- fiberglass filling, over-drilling, countersunk through-bolts, etc. I think I'll just use 3M 101 and call it good. There doesn't appear to be any reason to use an adhesieve. Just wanted to make sure nobody had had any bad experiences with 101.

Thanks again guys,

George

Peter · Post by **Peter** » Sat Mar 24, 2007 12:43 am

I went with the 3M 5200 Fast Cure. That's because the last set of thru hulls lasted 36 years, and the replacements are an even better quality.

I'm sure 3M 101 will do the trick. It has all the right attributes, according to the 3M web site, incuding easy removal ... just in case :-)

Post by **Tim** » Sat Mar 24, 2007 6:22 am

101 is a great sealant, and is more than adequate for through hulls. My only complaint with 101, which doesn't apply here, is that it turns an ugly brown when exposed to sunlight. But it's easy to apply, easy to clean, and lasts a long time. And if you have to remove it, it's no trouble at all. It does stink to high heaven, though.

While you don't technically need the adhesive properties of a polyurethane on through hulls, it doesn't hurt. I recently used 4200 polyurethane on through hulls for the first time; 4200 bridges the "gap", as it were, between polysulfides (101) and the essentially permanent polyurethane (5200).

4200 has about half the adhesive strength of 5200.

I consider through hulls to be essentially permanent fixtures, assuming that one uses quality materials and good installation practice, so the permanance of something like 5200 can be justified here, in my opinion. But it's probably unnecessary.

Figment · Post by **Figment** » Sat Mar 24, 2007 7:14 am

I acquiesced to let the boat have some say in its own process, I let the cockpit drain hose tell me where it wanted the seacock to be. Of course, it wanted the seacock to be just about where the engine intake seacock was. Bedded in 101, I went below, jammed a tool in the thru-hull, put some arm into the wrench and out she came like butter. 90 seconds, maximum, and I get to re-use everything today when I find a new home for it.
Were a polyurethane bedding involved, I'd not be typing with a smile.

Of course just about anything will work. Dolphinite, bazooka joe, s*#@%*@e, dog slobber, etc.

mfasis · Post by **mfasis** » Sun Apr 08, 2007 8:06 pm

I am just about done with my pre-launch project list. Just a few items remain including re-bedding my SR Mariner knotmeter thru-hull. I pulled it out and cleaned it up because the backing block was rotted which caused it to leak when I first splashed last season. I am a little confused as to what I should bed it with. It is a plastic fitting. I have a few types of bedding compounds on hand.

BoatLife - LifeSeal
BoatLife - LifeCauk (not recommended for plastic)
4200 (not recommended for plastic)
5200

Of this list I would be more inclined to use 5200 but I really dont want to make this a "permanent" installation.

Does anyone have any recommendations?

Mark

Post by **Tim** » Mon Apr 09, 2007 6:03 am

There are different types of plastics, of course. Some plastics may be affected by polysulfides; some will not.

Since I don't know what you have, I have to suggest that you contact the manufacturer of your instrument to find out. I wouldn't recommend LifeSeal, so if your only other choice ends up being 5200 or comparable Sika product, that's what I'd use.

I've only used 4200 a couple times now, but it is also a polyurethane like 5200--just a lower-strength (and less permanent) version. It should be compatible with the same materials as 5200, and might be a good bedding choice.

mfasis · Post by **mfasis** » Mon Apr 09, 2007 2:15 pm

I put a call into the product support line and I'm waiting to hear back. I was able to find out that the fitting is made of acetal copolymer.