3M 847 sources

[kfa4303]

Just wondering where to get a small tube of 3M 847. I've been looking online, but seem to be getting wildly varying prices and it often costs as much to ship as to buy. Thanks.

 

[HighTrim]

Re: 3M 847 sources

Im not very up to date on my American retailers, but I do believe you have Fastenals in your area do you not?

I know for sure they carry it. Your local Johnny/Rude dealer will also be able to get it for you.

 

[oldybutagoody]

Re: 3M 847 sources

I got it here
http://www.jamestowndistributors.co...e=3M+Scotch-Grip+Rubber+&+Gasket+Adhesive+847

 

[nwcove]

Re: 3M 847 sources

i use permatex aviation " form a gasket".....its readily available , and ive never had a problem with it. ( i do get a pack of then modeler brushes from the dollar store as the brush thats connected to the lid is to large and messy for most ob applications)

 

[kfa4303]

Re: 3M 847 sources

Thanks for the suggestions. I actually used Perrmatex Aviation gasket maker this time (has the look and consistency of molasses, right?) and Permatex Ultra Black the time before that, but I'm still getting water in the gear case (yes, I checked the shift shaft seal and cut the spaghetti seal correctly and seated the seals properly). I realize that sometimes these old motors leak a bit, and there's not much you can do about it (the clam shell gear case design with 6-7 holes in it isn't the brightest for something that's going to be submerged all the time), but I figured I'd try the 847 this time. If that doesn't do it, I guess I'll just have to drain and top off the gear oil after each trip, or get a new LU :/ I only paid $100 for the whole motor and I've spent almost that much on reseal kits and sealants at this point. Not to mention the new gears. The motor runs great, but the leak is annoying. The 847 is the only thing I haven't tried. Although, I did find some OMC perfect seal No.4 online, but I'm not sure if that would work. It seems to look a lot like the Aviation Gasket maker, which seems awfully thin, but who knows.......

 

[HighTrim]

Re: 3M 847 sources

I have done a mountain of gearcases with the 847, and it truly is a great product. Wont help if there is damage where the seal rides the shaft of course, but seals up any/all mating surfaces to the housings.

It is also great for sealing the crankcase halves, so it is not only used for gearcases. The tube has many uses.

 

[kfa4303]

Re: 3M 847 sources

I think you're right. The gear case, gears and seal housings are all in great shape and function perfectly, but I think the Aviation gasket maker was just a bit too thin, whereas the 847 seems to be thicker based on the description and apparently dries to more of a rubber-like state which should hopefully help seal things up a bit more tightly.

 

[nwcove]

Re: 3M 847 sources

did you try upping the air on a pressure test with the lu submerged in a bucket? i have a couple lu's that still leak after a couple of re-seal attempts, but pass a pressure test, i just drain and top em up now. ( even tried spinning them with a drill....no oil in the case, in a bucket, pressurized...never a bubble.)

 

[kfa4303]

Re: 3M 847 sources

It actually makes me feel a little better and a little less crazy that yours still leak a bit nwcove. LOL! I know I've put everything together correctly, but the leak persists. I'd love to test it prior to installation don't really have a vacuum/pressure tester. I do have a bicycle pump which I could use to pressurize it, but I'm not sure how to get the pump valve to screw into the DRAIN/VENT holes? :/ Oddly enough, the oil it never seems to get fully displaced no matter how long I'm in the water. It's as if a certain amount of water leaks in then stops. I don't really mind topping off the oil. It's quick and cheap enough to do, but it would be nice to not have to worry about it. I've resisted the 847 due to the price, but there may not be any getting around it. I checked the Fastenal here in town and they don't have any in stock. Does West Marine sell it, or a similar product I could use?

 

[HighTrim]

Re: 3M 847 sources

Upping the air pressure actually aids in sealing and makes it harder to locate a leak. 8 to 10 psi is all you need.

I have been pretty successful sealing so far. As long as the shafts are good, it should be able to be sealed up tight, no matter the age. Ive had to change a couple shafts from parts motors which were damaged, but afterwards they held strong. No leakers yet, knock on wood. The 847 is great as making worn housings useful that were chipped or cracked, where I think other gasket maker type sealers would eventually fail.

 

[HighTrim]

Re: 3M 847 sources

Kfa if you dont mind sacrificing your bike pump, cut the end off and use the end from a gear oil pump. Instant pressure tester! I used a bike pump that had a built in gauge.

 

[nwcove]

Re: 3M 847 sources

Upping the air pressure actually aids in sealing and makes it harder to locate a leak. 8 to 10 psi is all you need.

I have been pretty successful sealing so far. As long as the shafts are good, it should be able to be sealed up tight, no matter the age. Ive had to change a couple shafts from parts motors which were damaged, but afterwards they held strong. No leakers yet, knock on wood. The 847 is great as making worn housings useful that were chipped or cracked, where I think other gasket maker type sealers
would eventually fail.

i have pushed it to to 20 psi out of frustration lol. i do realize that the extra pressure will make seals ..seal tighter, but when youve replaced it all, and it still leaks, there is nothing to loose by adding a few psi and spinning the ds to look for a problem that causes a leak. ( i do it with no oil in the lu) with that being said.....even at low air pressure in the lu....no bubbles, jack it up 5psi, still no leaks. run it for a day , and there is signs of water. jmo....if its not worse than you are comfy with, just change out the oil after a good a good day of running.

 

[clanton]

Re: 3M 847 sources

Try auto zone, or Graingers.

 

[AlTn]

Re: 3M 847 sources

as per Clanton...W.W. Graingers will deliver it to your door....only drawback here is that they require an account name...I coat the skeg to gearcase screw threads and the bottom of the screw heads as well...kinda messy but quick wipe up minimizes the cosmetics...acetone or carb cleaner spray will help dissove it and allow a cloth to wipe it off, paper towels or shop towels are not suitable in my experience as they shred to easily...good luck as it gets frustrating at times dealing with water intrusion

 

[kfa4303]

Re: 3M 847 sources

Thanks for the suggestions Clanton. I'll check 'em out. I'll follow your advice on applying it anywhere and everywhere water mat get in too Altn. I'll keep y'all posted, but I don't think I'm gonna get much done until this TS blows over :/

UPDATE:

I think I found a 5 oz. tube for $16, free shipping and will arrive next day from Graingers. Sweeeet. Thanks Clanton.