mounting blocks in bilge - material?

[nfbr]

If you want to mount bilge pumps etc, by gluing mounts to the hull / stringers and constructing brackets etc

What material for the brackets? Assuming they will get submerged regularly.

Ply - rots
Starboard - won’t glue to hull
Timber - rots
Expanded PVC board - maybe
Foam core glass - maybe. Labour intensive
Stainless - welding needed
Aluminium - corrosion
Other?

Thanks

[Dsanduril]

Any of the structural fiberglass sheets? G10 is the one that gets thrown around a lot but is overkill for most things, its lesser brethren would be fine. Not cheap, but small amounts for brackets and mounts aren't bad.

https://www.eplastics.com/fiberglass...structural-frp

McMaster-Carr also has a wide selection.

[coopec43]

I've mounted my bilge pumps on plastic/nylon/? "boards". The pump is then lowered to about 6 in. from the bottom of the bilge and secured in place by a hand "nut". I can easily lift the bilge pump for cleaning the bilge and the pump is not immersed in water.

[nfbr]

Originally Posted by coopec43

I've mounted my bilge pumps on plastic/nylon/? "boards". The pump is then lowered to about 6 in. from the bottom of the bilge and secured in place by a hand "nut". I can easily lift the bilge pump for cleaning the bilge and the pump is not immersed in water.

How are the bolts attached to hull?

[coopec43]

Originally Posted by nfbr

How are the bolts attached to hull?

What do you call the structure that goes vertical down the bilge? Ribs?


If you can't work out what I have done I'll get up into the yacht and take a photo.

[Benz]

Originally Posted by coopec43

What do you call the structure that goes vertical down the bilge? Ribs?


If you can't work out what I have done I'll get up into the yacht and take a photo.

We call them "Floors"

[Sand crab]

These are ribs.

[LittleWing77]

Originally Posted by Sand crab

These are ribs.

Those are actually more properly called "frames" in sailboats, although in more modern production-style construction, it seems the are now captured by the "grid" (which is what the structure looks like now).

Anyway, what he's talking about is attaching the bilge pump platform to the frame - or as Cooper says - to the floors. It all depends whether he's attached it to the side or the base of the platform he fabricated.

Fair winds,
LittleWing77

[skipmac]

Why not just build a little platform from fiberglass cloth and polyester resin. My boat came with a couple of these to mount shower sump pumps, shaft lock etc. All have been submerged frequently and all are good as new.

[Joli]

I grind to bare fiberglass a spot in the bilge where I want to mount something then use a thickened epoxy to glue a G10 plate in that location. It's best to drill and tap the G10 prior to installation. When mounting your gear use lanolin or TefGel on the thread to minimize corrosion. Repaint to match the bilge but be careful not to get paint in the threaded holes.

[coopec43]

Thanks Benz


Here it is here

[nfbr]

Originally Posted by skipmac

Why not just build a little platform from fiberglass cloth and polyester resin. My boat came with a couple of these to mount shower sump pumps, shaft lock etc. All have been submerged frequently and all are good as new.

How to build a nice square flat plate without a form.

[Sparx]

Originally Posted by nfbr

How to build a nice square flat plate without a form.

Method one: Lay a sheet of polyethylene film on a flat surface. Wet out glass cloth with epoxy. Lay cloth on film. Add additional layers to achieve required thickness. After cure cut to final shape with band saw. Peel off plastic.


Method two: Chose a suitable size container of just right dimension such as a milk jug or old leftover container to use as a form. Coat with PVA mold release or mold release wax. Pour in epoxy mix filled with chop fibre or layers of cloth to desired thickness. After cure peel off form.

[foufou]

I take a small piece of thin G10 and screw the pump on top of that for a base, then attach a 1/4" fiberglass rod to the bilge pump with hose clamps. The fiberglass rod is cut to a length such that it holds the pump to the bottom of the bilge by pushing against the under side of the cabin sole. That way I can retrieve the pump by un-springing the rod with the pump attached and pulling it up as otherwise my bilge is too deep to reach the pump. This has worked well for years and is fairly simple to implement. Foufou

[Flamehand]

Reconstituted plastic (garden) decking floorboard is readily worked and available and fully weatherproof.