Jump to content

Fastening to the underside of a cores cabin top


Recommended Posts

A portion of the original headliner in my boat was Masonite wrapped in vinyl screwed up into the cabin top with sheet metal screws. 

The Masonite has disintegrated and I’m not that big a fan of the vinyl wrapped Masonite to begin with, so I’m hoping to skip the vinyl wrap and replace the vinyl wrapped Masonite panels with a cellular PVC sheet like Azek. As I think about attaching it, I’m thinking there’s got to be a better way to hold the new panels other than screws driven into the cored cabin top. Maybe some kind of stud epoxied to the underside of the cabin top? Any suggestions? 

Link to post
Share on other sites

What I did with one boat I owned was epoxy some thin furring strips (about 1.5" x 3/8" thick) to the underside of the cabin top. 

Then I screwed the expanded PVC (Sintra in my case) to the furring strips with varnished wood battens to hide the seams and around the perimeter. The panels were flexed upward to the curve of the cabin top.

Velcro is hard to get to stick the PVC stuff he's planning to use. Works better with thin painted plywood door skins.

  • Like 4
Link to post
Share on other sites

Also what Zonker said about using Sintra (or any other sign-quality expanded PVC foam board), not Azek. Azek is too thick and too heavy. you're looking for 3mm or 4mm to maintain the ease of cutting and the flexibility.

Here's how mine turned out:

 

 

After.jpg

  • Like 3
Link to post
Share on other sites

Velcro works fine on light, thin panels. If light and thin they need to be curved a bit to keep from sagging. On mine they are furred down a bit to hide the deck hardware thru bolts, the joints are handled with visible trim.

 

3vHVSpS.jpg

  • Like 1
Link to post
Share on other sites
12 hours ago, SloopJonB said:

Velcro

Velcro DUAL LOCK.  This shit is not your old school crappy velcro.  It's insane.

 

Genuine 3M Dual Lock SJ3550 Type 250 VHB Black Reclosable Fastener, 1" W x 12" Indoor/Outdoor Mobile E-Zpass Mouting Strip

  • Like 2
Link to post
Share on other sites
30 minutes ago, DDW said:

Velcro works fine on light, thin panels. If light and thin they need to be curved a bit to keep from sagging. On mine they are furred down a bit to hide the deck hardware thru bolts, the joints are handled with visible trim.

 

3vHVSpS.jpg

Ok, I have to ask.  I have a catalina 30 and the ceiling is looking like shit.  But the through bolts are all lock-nuts so they are like 1/4" thick.  So you put strips of woods in as stand-offs to keep the sintra off the actual ceiling and give clearance for the bolt heads?

Link to post
Share on other sites

Correct. Since most of the hardware is outboard near the companionway you could also let the new panels touch the existing inner skin closer to centerline (to avoid loss of headroom)

But with a molded liner why don't you just paint it?

Link to post
Share on other sites
1 hour ago, Grrr... said:

Ok, I have to ask.  I have a catalina 30 and the ceiling is looking like shit.  But the through bolts are all lock-nuts so they are like 1/4" thick.  So you put strips of woods in as stand-offs to keep the sintra off the actual ceiling and give clearance for the bolt heads?

again, what zonker said. I used sintra because behind the overheads are wires and raw glass. Cat 30, paint :)

Link to post
Share on other sites
2 hours ago, Grrr... said:

Velcro DUAL LOCK

It sticks to itself quite well. It's the sticking to the plastic that can be challenging.

I was on sea trials on a fast powerboat. Headliner was 3mm plywood covered with vinyl, held in place by super velcro. Every few big waves we slammed into a new panel fell down :)

Link to post
Share on other sites

Velcro is fine. The workings of pressure sensitive adhesive are a mystery to me. I do the ritual cleansing and perform the rites of adhesion methodically and patiently. Sometimes it works. Sometimes it doesn't.

Link to post
Share on other sites
16 hours ago, Zonker said:

What I did with one boat I owned was epoxy some thin furring strips (about 1.5" x 3/8" thick) to the underside of the cabin top. 

Then I screwed the expanded PVC (Sintra in my case) to the furring strips with varnished wood battens to hide the seams and around the perimeter. The panels were flexed upward to the curve of the cabin top.

Velcro is hard to get to stick the PVC stuff he's planning to use. Works better with thin painted plywood door skins.

I did the same thing with 1/2" and friction fit polystyrene insulation between the furring strips.

Link to post
Share on other sites

Check a local sign shop - place I bought some from had a big stack of it for their own use but were happy to sell a few sheets.

  • Like 1
Link to post
Share on other sites

Quick,  I used pvc bead board on the walls in my aft cabin.  I’m thinking it might be an option for a future headliner replacement.  But I’d have to epoxy in some extra tabs to support with out sagging

37337294-7E06-4824-BFED-5C5EE588CC9E.jpeg

beadboard foreaft.jpg

 

Link to post
Share on other sites

I thought about the pvc beadboard overhead as well. There's a video where a couple did that. If you don't get the seams exactly right, they are really noticeable.

for the Sintra, don't get hung up on the brand name, but yes a local sign shop or industrial provider should be able to get what you need. It should cost you about $25 per 4x6 sheet. If you order it online, the shipping will be around $200 or more. Definitely a good time to shop local.

Link to post
Share on other sites
5 minutes ago, Quickstep192 said:

I scoped out a product called Veranda at Home Depot. It's 1/4" thick, fairly light and comes in 2x4 or 4x8 sheets. 

 

https://www.homedepot.com/p/Veranda-1-4-in-x-24-in-x-4-ft-White-Reversible-PVC-Trim-Sheet-H060XWS6/312995340

 

 

1/4" is 6mm, twice the sintra thickness.

if like me you were replacing vinyl over foam and plywood, then 6mm is too thick to re-use the battens and spacing of the old headliner. if you're starting from scratch, it may be ok. I didn't like the pattern on the Veranda, and it's heavier than you think because it's solid.

Link to post
Share on other sites
  • 3 weeks later...
On 5/14/2021 at 10:27 AM, DDW said:

Velcro works fine on light, thin panels. If light and thin they need to be curved a bit to keep from sagging. On mine they are furred down a bit to hide the deck hardware thru bolts, the joints are handled with visible trim.

 

3vHVSpS.jpg

What material did you use for the liner?

Link to post
Share on other sites
2 minutes ago, Grande Mastere Dreade said:

 

Slip neighbor is specifically looking for the 'plank grooves' in the material DDW.

Personally i prefer the flat sintra - and i will be using it to resurface 2 bulkheads, but they want the look DDW had.

 

thanks for the reply though !

 

 

Link to post
Share on other sites

I spent some time today trying to buy a sheet of Sintra. The first two places I called won't sell it to me 'cause I ain't nobody (not a business). I finally reached a retail sign store who will order me a 4x8 sheet of PVC sign board for $165. A 4x8 sheet of 1/4" thick Azek is $45 at Home Depot. Do you guys think Sintra is that much better? 

-or-

Is there another tree I can bark up to find Sintra or other Expanded PVC at a better price?

Link to post
Share on other sites
4 hours ago, dfw_sailor said:

Slip neighbor is specifically looking for the 'plank grooves' in the material DDW.

Personally i prefer the flat sintra - and i will be using it to resurface 2 bulkheads, but they want the look DDW had.

 

thanks for the reply though !

 

 

I do not know the brand, it is a foamed PVC material with a matte finish. It comes in plain sheets, the grooves were cut on a table saw to simulate the T&G appearance. I think you could do the same to any material that was homogeneous. The sheets are about 1/4"/6mm thick, grooved approximately 1/3 of the way through, table saw set at 45 deg spacing approximately 2" or whatever looks good to you. 

Link to post
Share on other sites
7 hours ago, DDW said:

I do not know the brand, it is a foamed PVC material with a matte finish. It comes in plain sheets, the grooves were cut on a table saw to simulate the T&G appearance. I think you could do the same to any material that was homogeneous. The sheets are about 1/4"/6mm thick, grooved approximately 1/3 of the way through, table saw set at 45 deg spacing approximately 2" or whatever looks good to you. 

Awesome,  thanks for the detailed reply!

Link to post
Share on other sites
12 hours ago, DDW said:

the grooves were cut on a table saw

Shannon had a 'mold' for making fiberglass ceiling panels with these grooves - quite nice looking, but I suppose too much work for a one-off project.

Link to post
Share on other sites
13 hours ago, DDW said:

cut on a table saw to simulate the T&G appearance.

I've seen a router sled used as well - with a ridge on the bottom to follow the previous groove. 

Is there any issues with the exposed "foamed" core of the PVC?

Link to post
Share on other sites

I say foamed but I don't actually know the manufacturing process. There isn't any noticeable foam cells in the grooves, in fact it is smoother and shinier there than the matte finished surface. The panels are too light to be solid PVC though, so I assumed they are foamed in some way.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...