help - plywood adhesive

[jc.fuego]

I recently found some water damage around an electrical cord that runs through the mast and into the boat. I am cutting out some damaged plywood that was glued to the bulkhead. I also had to pull down a section of headliner to remove the plywood.

The headliner is wrapped and stapled to a single sheet of plywood. The plywood side is glued to the fiberglass ceiling and held in place by stringers. The plywood on the bulkhead that I cut out was glued in-place, but I am not sure what material it is glued to on the bulkhead. It is not structural.

Can someone recommend an adhesive I should when I replace the plywood on the bulkhead and put the headliner back in?

I like the idea of being able to pull down the plywood sheets the headliner is fastened to without ripping the plywood because the adhesive is too strong. Don't know if that is possible though. Thanks!!

[belizesailor]

Headliner to Plywood its common to use spray adhesive like 3M 77.

Use marine grade plywood this time around.

[belizesailor]

Originally Posted by belizesailor

Headliner to Plywood its common to use spray adhesive like 3M 77.

Use marine grade plywood this time around.

...if you want to be able to remove this headliner board in the future then dont glue it to the hull. Glue the headliner to plywood backing and devise a way mechanically attach this headliner board assembly so that it can be removed when needed.

[tkeithlu]

If you want to remove it, you need a mechanical attachment rather than adhesive. Assuming there is nothing structural involved (I can't quite picture it, so I'll go with that) and that you have enough material behind it all to screw into, try flathead ss screws and trim washers:

https://www.mcmaster.com/wood-screws...rews-for-wood/

https://www.mcmaster.com/trim-washers

[Secondshift]

If screwing, an alternative to the trim washers could be screw caps.

A two piece plastic part that includes a base with snap cover.

https://www.westmarine.com/buy/fasco...SABEgJAMvD_BwE




Regards

[Cheechako]

Not sure I fully understand, but for the overhead liner, glue the covering to decent plywood 1/8-1/4". Glue 5/8-3/4 plywood strips to the overhead fiberglass so you can screw your headliner into that. Usually you cut slots in those so they bend well. Bondo works, that expanding Gorilla Glue might work. Thick epoxy of some sort would likely work. I used 5200 once, but you have to hold it in lace somehow. That way you can take the overhead off anytime you want.

[vanderd]

several years ago we redid the interior of our 44 ft Cat. The ceiling panels were previously screwed to the overhead with little plastic caps over each screw. I thought it looked a little amateurish. I ended up using a hook and loop material from3M. Similar to the hook and loop used to attach EZ pass transponders to a car’s windshield. I used 5200 to hold the strips of hook and loop in place. They’ve been up for 7 years still holding perfectly and occasionally I’ve had to remove a panel and they go back easily. The tape wasn’t cheap and I believe 1” holds 60 lbs. I’m sure I used more than needed. I generally tend to overbuild.

[adjo]

stick on Velcro tabs are used on some production boats

[kupo2kupo]

Our Beneteau uses a combination of "Dual Lock Reclosable Fasteners" (similar to Velcro but sturdier) and a few strategically placed screws to mount vinyl covered thin plywood panels to a plywood sub-structure. Works pretty well.
The fasteners are also known as "Snap-Together Mushroom-Head Fastener" at McMaster Carr.

[Uncle Bob]

Originally Posted by Secondshift

If screwing, an alternative to the trim washers could be screw caps.

A two piece plastic part that includes a base with snap cover.

https://www.westmarine.com/buy/fasco...SABEgJAMvD_BwE




Regards

Much of the fastening on my boat was done using these, I too found them somewhat less than pleasing and have been replacing them with raised head countersunk stainless screws. To my eye, much better.

[Franziska]

They make an industrial type double hook tape (3M Dual Lick SJ 3550) which replaces the felt side of velcro by another type of hooks.

Much sturdier than classic velcro and used in many production boats to attach headliners.

[Dougtiff]

I used to work on Mega Yacht's in Florida, and we used VELCRO to hold the overhead panel's in place, as most of the wiring passed thru the overhead, and needed to be accessed easily, industrial grade is available.

[jc.fuego]

Originally Posted by Dougtiff

I used to work on Mega Yacht's in Florida, and we used VELCRO to hold the overhead panel's in place, as most of the wiring passed thru the overhead, and needed to be accessed easily, industrial grade is available.

Thank you, this sounds like the best solution. The headliner is already held up on one side by a stringer and the opposite side by trim, so I just want a little something extra in the center of the board.

In terms of the piece of plywood (aesthetic) I need to replace on the bulkhead, do you have a suggestion for adhesive? Looks like some have suggested Bondo, and others spray adhesives.

[jc.fuego]

Originally Posted by Cheechako

Not sure I fully understand, but for the overhead liner, glue the covering to decent plywood 1/8-1/4". Glue 5/8-3/4 plywood strips to the overhead fiberglass so you can screw your headliner into that. Usually you cut slots in those so they bend well. Bondo works, that expanding Gorilla Glue might work. Thick epoxy of some sort would likely work. I used 5200 once, but you have to hold it in lace somehow. That way you can take the overhead off anytime you want.

Thanks, I only need to replace the plywood on the bulkhead. The headliner & plywood it's attached to is intact, I just need to re-mount it after I fix the bulkhead. I will keep this in mind if I need replace the headliner completely in the future.

[jc.fuego]

Originally Posted by belizesailor

Headliner to Plywood its common to use spray adhesive like 3M 77.

Use marine grade plywood this time around.

Thanks, the headliner is already fastened to plywood. The plywood I need to replace and glue is on the bulkhead. I also need to re-mount the headliner board - from other comments, I think velcro is the best for this.