marine caulk (water proof)

ray estep

Seaman
Joined
Oct 1, 2006
Messages
67
I am installing a bilg pump in my boat, and the instructions on the pump say don't use anything that smells like vinager or it will cause corrosion. I will most likely have to mount it to the transom, so I want to use the best water proof suff out there to protect it for and as long as posible. My boat is a fiberglass trihull but I believe there is wood in the transom. The transom is in great shape so I don't want that to change. Anyone with knowledge of a product or products that are specially suited for this. I would apriciatre your help! Or any tips on mounting bilge pumps is also appriciated. Thanks

Ozarks R&R
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: marine caulk (water proof)

what a lot of people do is use the 2 part epoxy, (walmart) and glue the base of the bilge pump to the hull bottom. using no fasteners, must be clean and dry.
 

ziggy

Admiral
Joined
Jun 30, 2004
Messages
7,473
Re: marine caulk (water proof)

from what i read, caulk aint supposed to be used, generaly in boats. but, my bilge pump had come loose from wherever it was attached to in my boat and was just floating(so to speak) around down in the bilge. it's to late for me, i used auto/marine sealant, 100% silicon. it does smell like viniger i guess. so far so good, though it aint been thru the ringer yet to see how long it works as i just recently did this, or what corrosion it may cause too. so, corrosion ay? that i hadn't considered. how will my plastic bilge pump with marine caulk siliconed to my fiberglass boat bottom create corrosion? maybe so, i don't know. i'd think it'd be hard to argue with the mfg. of what ever product ya got. i will have to let some time go by before i can say if it worked or what problems i created by useing that type of a product. i thought about epoxying it down, but thought if i ever wanted to remove it, for whatever reason, the silicon might be easier to get off. least that was my thinking........also thought about useing 3m 4200 i think it's called. i've never used it, but it sounds like a real good sealant that may be removable with effort.......
 

rickdb1boat

Supreme Mariner
Joined
Jan 23, 2002
Messages
11,195
Re: marine caulk (water proof)

If you're going to screw it in, I'd use the 3M 4200. Seals well and can be removed later on.....
 

QC

Supreme Mariner
Joined
Mar 22, 2005
Messages
22,783
Re: marine caulk (water proof)

I've mounted three just like tashasdaddy suggests and you can still pull the pump and replace with same if you only get the epoxy on the base . . . New builders use that method around here too.
 

ray estep

Seaman
Joined
Oct 1, 2006
Messages
67
Re: marine caulk (water proof)

Thanks for the help everyone! My father inlaw says he has his mounted to a weigthed piece of plastic which he puts right down in the lowest part of the bilge. He used led. I think I'm going to do the same. I would like to use brass if I can find a chunk and mold it to an ideal shape. Thanks again.

Ozarks R&R
 

SwampNut

Petty Officer 1st Class
Joined
Jan 9, 2006
Messages
325
Re: marine caulk (water proof)

3M 5200. It's permanent and waterproof. Easy to work with because setting time is extremely slow (one week for standard, one or two days for "fast" 5200.

I think laying a pump in the bilge with only weight to hold it in place is a very bad idea.
 

Autotech1

Petty Officer 2nd Class
Joined
Oct 25, 2006
Messages
195
Re: marine caulk (water proof)

Anyone ever try Liquid Nails? I wonder how well this would work. Removal should just be a matter of breaking the plastic and sanding the adhesive down dont ya think?
 

SwampNut

Petty Officer 1st Class
Joined
Jan 9, 2006
Messages
325
Re: marine caulk (water proof)

Wait, are you talking about gluing the pump itself into place? The pump should be attached to a piece of sealed wood or Starboard, then that is attached permanently to the hull. The pump can then be removed easily.

Also many adhesives such as silicone do not bond to plastics.
 

ray estep

Seaman
Joined
Oct 1, 2006
Messages
67
Re: marine caulk (water proof)

I've desided I'm going to get a plastic cutting board

cut it in half then drill two holes in both halves that line

up on both boards. Then stick stainless steal bolts

though one half and glue it to the hull with 2 part epoxy.

Then attach the base of the pump with stainless steal

screws to the second half of the cuttung board. Then

attach the two halves with wing nuts and lock washers.

I'll also make sure the bolts are attached in a way that

will not allow them to spin freely if I need to remove the

wing nuts to work on or replace the pump. I'll probably

do this by using hex head bolts and heating them and

then pushing them into the bottom board. There are

also some washers with teeth on them I may try. You

can usually find them at the bolt and nut store.

Thanks agian Ozarks R&R
 
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