3M Silicone Paste, the “Secret Sauce” of Marine Mechanics
Assembling hoses is not one of my favorite jobs on a boat, always tough to get the hose to slide on the fitting no matter what lube I tried.
This last spring I re-powered my boat. When it came time to start putting the hoses on, the mechanic at the boatyard brought along a jar of 3M Silicone Paste to assemble the hoses with. When I ask him about the paste he referred to it as “The Secret Sauce” when pressed for more info there was the normal kidding “if I tell you I would need to kill you” stuff.
The 3M Silicone Paste really did make the assembly easier and faster. A bit of the paste on the fitting and sometimes just inside the hose and the hose slid right on. I was amazed. I ask the mechanic for some more information about this “Secret Sauce” and it’s use. He has been using the Silicone Paste for several years to help assemble hoses and said it has really made his job easier and the paste also reduces / eliminates the corrosion that seems to form around metal raw water fitting. He said that it was also great for head hose, warm the hose a bit and with the 3M Silicone Paste on the parts just slip right together. I have not tried this yet on head hose, but I do have some head hose to replace and the last time I replaced some hose it was not a pleasant assembly experience, so I am hoping the paste works well on the head hose.
I have used the Silicone Paste on a few hoses and was impressed. I also like that is it listed as a Dielectric Paste that will help prevent corrosion on electrical terminals.
The Silicone Paste can also be used on O Rings, 3M lists several uses for the Silicone Paste, Dielectric Grease, Lubricates, Prevents Oxidation, Safe on Metal, Rubber, Weather Stripping and Plastic Parts. Other 3M suggested uses are on Brake systems, Ignition systems, Electrical terminals, Rubber bushings and more from the label and manufactures web page. It is designed for use in wet, dusty, dirty and other extreme conditions, is 100% solids and non-melting.
The Silicone Paste is part of the 3M Car Care automotive line, I have not seen it in marine supply stores so you might need to look at your local automotive parts store for it, some boatyards do carry it, several automotive parts stores have the Silicone Paste in their warehouse and can have it delivered to the retail store in a day or so.
3M Silicone Paste Part No. 08946 for the 8 oz. (226 g) size. About $30.- depending on where you buy it.
Disclaimer / Note: Many hoses on a boat can be a life safety issue if they are not installed correctly. The boat owner needs to make sure they have selected the proper hose, hose fittings and that the installation is done correctly. If a hose below the waterline fails, the boat could sink or be damaged, the same for engine cooling hoses. It is up to each individual boat owner to make sure the entire installation is done correctly with the proper materials used to keep your boat and crew safe.
Thanks for your interest in and support of Boating Safety
– c / m –
Boating Safety Tips, Tricks & Thoughts from Captnmike 
Be sure to Google “silicone contamination” before you get too in love with the stuff. You must be excruciatingly careful not to accidentally get it on unwanted surfaces.
Personally, I use a bit of dish soap. Nearly as effective, and much less of a chance of contaminating something.
Good point on the getting silicone on the wrong surface
Thanks
I have had surface contamination issues with mold release agents in the past where the person ahead of me did not do a good job cleaning a surface and the sealant would not stick (sort of looked OK from the outside but liquids would seep through). After a very thorough cleaning and scrubbing the sealant did adhere correctly and the leaks stopped. Poor surface cleanup is something that many boat manufactures seem to skip a bit (a lot maybe) during assembly. But I have also had surface contamination issues in other industries and with other compounds (some thread lubricants seem to get on EVERYTHING!!!)
So again your point about being careful where any lubricant gets is important – thanks again for stopping by an helping
One of the most important reasons to lube the hose fittings is to facilitate the hose removal at some time. Trying to remove a hose that has been in place for years and likely heated and cooled thousands of times is a chore of the highest level. And always in an inaccessible location.
In addition I always file off some of the heavy ridges on nipples and connectors.
I have had to cut quite a few hoses off the fittings and have also taken down the ridges a few times
Thanks for the extra info
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