Adhere Plywood Facing to Bulkhead.

[PeteLivez]

Hi All,

I am replacing plywood facing on my fibreglass bulkhead. It was previously adhered with a black adhesive sealant of some sort. Done without any screws or other fixing and it did the job very well taking considerable effort to remove.

Considering my options for fixing the new plywood. What is the best type of adhesive sealant for a strong bond and preventing water getting behind the panel?

I believe Butyl Tape gives good sealant, but would it give sufficiently strong bond?

 

[jamie N]

Recently I used CT1 (clear) for a very similar job. I'm a bit if a fanboy for the stuff.

 

[Rappey]

What about using self adhesive polymeric pvc film or similar ?

 

[Stemar]

For something like that, I'd use any of the exterior grade No More Nails type of product. There isn't a huge strain. CT1's very good, but it ain't cheap! My depth transducer was held in place with the Gosport pound shop's version for years

 

[Tranona]

If the ply is thick (9mm+) it will be stable so using an adhesive sealant like CT1 which requires pressure but not heavy clamping would work. However, presumably you are removing the instruments so should be able to arrange clamping struts to apply even pressure against the bulkheads while the adhesive cures. I have done similar using thickened epoxy and used battens screwed around the edges and filled the holes afterwards with matching plugs. Effective though it was I think I would use the adhesive sealant method now.

 

[PeteLivez]

Thanks for the replies so far. CT1 looks good.
Assuming we are talking about the same stuff it doesn't seem expensive to me...?

 

[waynes world]

I was a big fan of CT1 then Sikaflex 291i but now i use Puraflex 40 on naear all these kinds of jobs. Dam good stuff.

 

[Tranona]

Thanks for the replies so far. CT1 looks good.
Assuming we are talking about the same stuff it doesn't seem expensive to me...?

View attachment 130983

That is the stuff. Rather messy to use on a large area like your bulkheads as you will need a spreader to make sure it is even across the panel. Mask around the contact area and use gloves as it seems to have an affinity for bare flesh!

 

[PeteLivez]

That is the stuff. Rather messy to use on a large area like your bulkheads as you will need a spreader to make sure it is even across the panel.

I was thinking I could just put a large bead around the edge of the panels rather than spread over the whole board, what do you think?

 

[waynes world]

I was thinking I could just put a large bead around the edge of the panels rather than spread over the whole board, what do you think?

myself i would apply a 8mm bead within the 25mm edge of the board of the Puraflex 40. first though seal all the ply with epoxy resin. on the back and edges and front unless your varnishing it. .

 

[PeteLivez]

myself i would apply a 8mm bead within the 25mm edge of the board of the Puraflex 40. first though seal all the ply with epoxy resin. on the back and edges and front unless your varnishing it. .

8mm sounds good. Thanks.

Currently applying second coat of epoxy.

 

[V1701]

Yes CT1 or OB1 from screwfix, they're essentially the same stuff and very effective, I've used them both for various jobs. A generous bead around the edge maybe an inch or so in, rest something heavy against it while it goes off & then a neat bead along the top edge from outside to stop water collecting there I think is what I'd do...

 

[Tranona]

I was thinking I could just put a large bead around the edge of the panels rather than spread over the whole board, what do you think?

By the looks of your photos you have lots of holes and fastenings in the panels. I would be happier if it was bonded all over.

 

[bluerm166]

The plywood will remain a maintenance issue.Fine if you like stripping and varnishing but if not take the opportunity to face the bulkheads with 2mm fibreglass panels supplied by East Coast Fibreglass which have a superb finish .Use the cutouts for clamping into position over resin .

 

[PetiteFleur]

And then make canvas covers so that you don't have to revarnish every 2/3 years. I've only had to revarnish my washboards and hand rails once in 15 years. Well worth the effort of making simple covers.