Rebuilding a hardtop

[healhustler]

I've done about as many patch jobs on my old hardtop as I would like to do, using every 3M and West Marine Product made. *Now, I considering biting the bullet for a re-skin job, or perhaps even a new hardtop if the estimate suits me. *Anyone done one of these lately. *The underside (interior side) is beautiful. *Top skin has many de-laminations, cracks, etc., and the camber is gone. *Any advice would be appreciated.

 

[Anode]

Here's a picture from a couple of years ago. I sanded off all the nonskid on the pilot house, reglassed, *added the hatches primed and painted.

Lot's of work but worth the effort.

 

[healhustler]

Chip: Of course, it's a beautiful job, just like everything else you've done with the boat. Tell me, did you have a good shaped hardtop to begin with? I mean, did it have any camber left, or was it a well where water could pool. Mine has several places that don't drain entirely. And what are those seams? Are they the drain canals? When are you going to be ready to splash that thing, anyway. By now, it surely must be the best of it's kind.

 

[Anode]

Above is the original.

The areas that I reglassed was originally a patterned nonskid that was in*poor condition and the po had painted over it. I sanded it down and reglassed with a single layer of fiberglass mat and left it smooth. Those areas are raised from the 'seams'.* The roof does have a lot of crown in it for drainage and seems to drain well. A lot easier to keep clean than the old nonskid.

Looks like we will wait until spring to splash now. Finishing up the interior. Getting my helm station back in this weekend. Still have to install the auto pilot and inverter. Thanks for the compliments, we're really proud of her.

 

[healhustler]

Anode wrote:
**The roof does have a lot of crown in it for drainage and seems to drain well. A lot easier to keep clean than the old nonskid.

*

That's just my trouble. *My hardtop is ribbed, and although it seems plenty strong when I walk on it, the top skin is in terrible shape. *I figure I'll have to peal it off, clean and/or remove any questionable parts inside, then foam the whole thing, leaving a good crown. *Finishing up with a couple layers of mat over the foam would probably do it. *I'd have to wait till the rainy season is over to start, though.

 

[HopCar]

Healhustler, It's odd that your hardtop would lose it's shape. That sounds like structural problems. Does it have a foam or balsa core? It could be that the core has rotted or become water saturated. Did you talk to John Spenser or any of the other boat yards? What did they say?

I see you're onto the core idea before I could push the Submit button.

 

[healhustler]

Hopcar.....yes, Spenser was supposed to have his guy out here this week to look at it, but you know the way things are in Miami. Anyway, the inner liner of the hardtop is really nice in form and condition. It would be a shame to cover it up with a flat piece of glass or divinicell. There are some pre-fab panels out there too, but it looks like I may just do the outer skin in my garage (kind of like making a glass pan) and then trim the old skin off, fill between the ribs with with closed cell foam, then attach the skin with West System. It's the only way I can think of to preserve the interior side. Still, I'd like someone to talk me out of it cuz I've got better things to do. I was out there caulking up some cracks today with some 4000.

 

[FF]

If the top layer has come free from structural foam, the bottom probably has too.

Building a new hard top is quite easy .

The cost will be the sq ft of core material, we use Nadia Core in budget jobs , and the cost of the GRP layers.

Our preference is for 3/4 oz matt and 24 oz woven roving. 1 1/2 or 2 inch Nadia Core.

If the underside is to be finished 5 layers M,R,M,R,M would be the choice for both sides.

Lay one side up on any really flat surface , it will be the inside,, flip it over carefully , install 2x lumber under the limp shape to create what evelr camber you desire.

Then lay up the top surface.

It will weigh about 3 lbs per sq ft , so a bunch of folks can lift it , depending on size. 10ft x 10ft is a case of beer sized job.

 

[Steppen]

With the help of a good friend who is a skilled carpenter,*I built a 12 X 11 foot hardtop to cover the cockpit on our boat.* That was in 2005 and I learned alot about epoxy, paint, filling, fairing and core material.* The first photo is the original open cockpit of our boat.* The second photo is the finished product installed with canvas.* The third photo is a view of the underside of the hardtop.

We used cardboard to roughout the crown on the top then built a template out of cheap plywood.* Took the crown template to the boat three or four times to get just the right crown.* Once we had the crown the way we wanted it we built the skeleton frame for the hardtop out of marine grade 3/4" plywood sistered together to create 1 1/2" stringers and side rails.* This then was also taken to the boat and the proper fit confirmed.* The plywood was epoxied and screwed together for a permanent bond.* The stringer are about 18" apart.

Once the framework was done I laid two layers of 1/4" marine plywood over the entire skeleton.* I used 1/4" since I needed to bend the plywood to fit the crown.* The first layer was applied using epoxy and screws and allowed to harden.* Then removed the screws, applied more epoxy to the upper side and laid down the second skin.* This was also screwed down.*

Once everything had cured we applied more epoxy plus fiberglass fabric to the whole structure, topside and bottomside.* Much epoxy, much fairing, sanding and filling with West Systems fillers.**I also took into consideration the location of underside*cockpit lights and the locations of stanchions to support the frame when*finally installed.*

Once the*fiberglassing and fairing were done I primed everything with Interlux primer then topcoated with Interlux Brightside one part paint.* The topside received primer plus Interlux Interdeck paint.*

The top was transported to the marina on*a flatbed (I didn't want to*dent or scrape it trying to lay it in a pickup).* We used the marina boat lift to gently drop the top onto the boat.* Had about 6 guys on the stern of the boat holding up the top while one guy was on the dock sawing 1" stanchions to the right length and I was positioning and drilling for the stanchion bases.* I think the top ended up weighing around 300 lbs.* It was a six man carry.

The top is supported by four 1" stainless stanchions plus the forward edge overlaps the original top by about 18".

I have had no delaminations and no problems with the top since installation in the spring of 2005.* We added canvas in the fall of 2005.* If I had to do it again I would have used some of the Nadia or foam core material instead of plywood.* The plywood, though heavier, has proven to be very tough and we have no problems walking on the new hardtop.* Was very happy with West Systems epoxy.

*


-- Edited by Steppen on Sunday 4th of September 2011 03:41:45 PM

 

[HopCar]

Healhustler, Spenser's fiberglass guy was in my store last week. I think his name is Steve but I don't trust my memory very much these days. He is the guy who replaced my cockpit deck and installed new hatches. I was very pleased with his work.
Glass Tech boat yard has a reputation for good fiberglass work as well. You might want to get two or more bids on this job.

 

[healhustler]

Step: Outstanding job, so well matched to your original hardtop. True....the plywood is heavy, and frankly I'd rather not put any more wood in my boat than there already is. I'm sure I'll core it with one of the closed cell foams to save weight (it's pretty high up there). I think your boat may actually look better with the extension. Fine job.

Hopcar....Mike Davenport was the guy I was speaking to at Spencers. I've also spoken to Mario Jr. over at Campiones. Both will be quoting. I'll check out Glass Tech also, thanks.

 

[healhustler]

FF: Thanks for the simple explanation of the layout you'd use for such a top. Knowing the weight is quite helpful also. Sure wish you'd just come over and do it for me. Ever think of taking a vacation in Miami? LOL, great info. Thanks again.