Bonding to hull - Light and Heavy items

[nfbr]

If you wanted to attach things like shelves or light switches to the hull, without screwing into the hull.

What would you bond wood to GRP with?

2 Part Epoxy
Marine Fibreglass Epoxy
Thickened Marine Fibreglass Epoxy
Polyurethane Caulking (Sika etc)
Polyurethane Glue (Gorilla etc)
Construction Adhesive

Would you use anything other than wood for blocks? Seems starboard does not adhere well.

Thanks
Paul

[Benz]

Depends on the application and surface area available for bonding, but you can't go much wrong with thickened epoxy. You can buy it in tubes with a mixing spout so it squirts out all ready to go. Total Boat has a version; Pro-set is the best; there's another one called "six-ten" I think. None of them will take a whole lot of flexing, but for small things, they're OK. You can butter up the back side of the piece, leaving a corner or two clean, then put a dollop of hot glue on the clean corners and slap it in place. The hot glue holds it on until the epoxy sets.
Surface prep is going to be the most important thing.
I don't know the difference between your first three choices. What is "Marine Fiberglass Epoxy?" If it's laminating resin, then it won't do unless thickened.

[nfbr]

2 part epoxy - 5 minute Araldite / JB Weld etc.

[sailormed]

Devils glue "3M 5200".

[Chotu]

Looking forward to more on this. Especially of the non epoxy type of answer.

[Manateeman]

Plexus.
Only one issue. Removing anything stuck together with it. The company also gives great support to boatbuilders. Worth the money.
Makes 5200 look like kindergarten glue.
Happy trails to you
Mark and the manatee gang

[Coolerking]

We often use a beveled marine grade plywood pad of the size/thickness/strength needed to mount whatever you are mounting, use a low speed roloc pad to remove any coating on the hull under and around the pad, then using a thickened (peanut butter style) epoxy we stick it to the hull and then clean it up nice with a fileting tool (squeegee or a rounded paint stick).
We will often cover it with a light glass cloth and finish with peel ply to make it smoother for paint.
In the case of loaded hardware like pad eyes, stantion/winch/turning block bases we use the same method, but we use much heavier DB glass, at times it is vacuum bagged and we swap the wood for carbon fiber/G10/FRP on differing composite boats

[nortonscove]

Originally Posted by Manateeman

Plexus.
Only one issue. Removing anything stuck together with it. The company also gives great support to boatbuilders. Worth the money.
Makes 5200 look like kindergarten glue.
Happy trails to you
Mark and the manatee gang

I think for most things the 5200 will suffice. My experience is that nothing has held as tenaciously in the Marine environment. I have one harrowing story about it from when we built fishing boats for a living.

[Mauro47]

Depending upon the application, location, load capacity requirements and so on. There are many good products to choose from
One of the most effective in professional applications is CLICK BOND adhesive
It forms an almost instantaneous structural bond between almost any material.

[bcboomer]

I've had excellent results with the "Weld Mount" system. The AT-8040 is quick to use and I mounted my hot water tank to the side of the hull with it.

[Minggat]

For some things, the heavy duty double sided foam tape has worked well for me. I had a DVD player mounted vertically. Getting it off years later was not easy.

[Sparx]

Goop Marine adhesive does a great job with sticking mounting pads to GRP. Goop holds well but can be removed. Much less toxic than epoxy.

I also keep a tube of Plexus on board.

[Madehn]

5200 aka the devils glue- will hold and hold and hold- it also gets everywhere if you are not careful with it- be aware that after you open the tube in the caulking gun, you only have a few weeks before it manages to set up in the tube-- i use it to adhere wood strips to the hull the anchor anything i want into the wood strips. getting it off later is a BEAST, i usually use an ocillating saw and some heat. cleaning up when wet is easy- acetone on a rag works well. just dont let it dry and then try to clean up

[coopec43]

Originally Posted by Chotu

Looking forward to more on this. Especially of the non epoxy type of answer.

When I installed the sheaves blocks at the steering quadrant I sanded down the fiberglass each side of the quadrant (18 inch X 18 inch) and laid polyester/CSM. I then used polyester/CSM to fiberglass the SS angle to the hull.(I would have used 6 layers). (The mounts for the autohelm were done the same way)

The stresses on the sheaves at the quadrant could easily be 500kg but I'm confident they will hold.

[sailormed]

Originally Posted by Madehn

5200 ............. getting it off later is a BEAST, i usually use an ocillating saw and some heat. cleaning up when wet is easy- acetone on a rag works well. just dont let it dry and then try to clean up

I Use a solvent called DEBOND (or a similar name) with good results. Give it some time for penetration after applying it. The stuff will come free. Sometimes reapply a second layer.