Alternative material for teak hatch rebuild?

[Beausoleil]

In another thread, someone had a problem similar to mine: what to do about leaking teak hatches:

Originally Posted by MJH

I spent a lot of time last year trying to find replacement hatches for the four teak ones on my boat. None of the manufacturers I contacted had anything close to my hatch sizes and I don't want to start cutting new holes or have to refinish with new inside trim.

I then looked into having them made out of a non-wood, non-metal material and contacted a manufacturer. He was enthusiastic to do the job but his estimate was about the same price to have them made out of new teak because the sizes were unique requiring separate molds and the forward hatch is particularly large, a true escape hatch.

Then I started reading some of the postings of owners who had non-teak hatches and the problems they were having replacing or repairing theirs; metal doesn't appear to be the panacea for manufacturing trouble-free hatches everyone thinks it is...it is just accepted as standard these days.

In the end I will just replace my teak ones with new teak when the time comes. In the meantime I've had new covers made for them to maximize their remaining life.

~ ~ _/) ~ ~ MJH

I have the same problem - the teak hatches (four deck hatches and companionway and doghouse hatches) which need to be rebuilt. They're custom to my boat ('79 Formosa 51).

Do I rebuild them using teak? I could, but I'd have to maintain them more than I'd like in the future. But they sure are (were?) beautiful - these are pics from 10 years ago:




Do I replace them with a modern hatch? My wife has already vetoed that idea - maybe I should tell her she'll be in charge of future maintenance...

Because they're so damn heavy, I was contemplating rebuilding them using PVC - perhaps laminated (using fiberglass mat between layers for strength?, and then cladding them with thin teak strips (3/8" rather than normal decking thickness).

Two smaller hatches (20"x20") and the doghouse hatch have lexan lenses, but that shouldn't be a problem.

Would the laminating have enough torsional strength so that I could stand on the one hatch which is located under the mizzen boom? It's all teak decking on top similar to the companionway hatch pictured above, so I don't have to worry about scratching any lexan...

Would the weight savings from using PVC "outweigh" (pun intended!) the lesser strength of compared to that of teak? Would fiberglassing add enough additional strength without adding too much weight?

[Bill O]

We just did our new slider hatch and agree that you should stick w/the traditional look for your boat

To lighten the weight, you could ualso se HDU (high density urethane) board instead of PVC for the base. The HDU is fairly nice to work with and we have completed several products w/it including new hard dodger coamings and an aft hatch. The HDU will never rot out and fiber glasses well.

For the new companionway hatch, we did use 3/8" teak for most of the hatch covering except for the handle, lower board and sides edges. We do not stand on our companionway hatch (its under the dodger), but the aft hatch is just glassed HDU on the top and no problem walking on it.


Bill O.

[Cheechako]

Why are they not rebuildable?
I might replace overhead with aluminum hatches. But I'd rebuild the slider.

What type of PVC are you speaking of? Just sheet? I'm not sure glass sticks that well to PVC.
I think Lexan is heavier than Teak by a lot.
Quality (dry) plywood isn't that heavy really as a substrate.

[Calif.Ted]

I've always found it easier, less costly and more expedient to rebuild unless the hatch is total toast. I think that hatch may be made with the teak strips glued to a plywood base on the top section. Minor imperfections in older teak brightwork is just character when it's topped with a proper finish, like your "before" photo.

[BenBowSirocco]

Usually leaks are caused because its the caulking that has let go. Teak Decking Systems sells a single part tube of sealant you can fix them up with.

Be diligent in your preparation. Sealant is like any coating, preparation is 90% of the game.

[Beausoleil]

BenBowSirrocco: when we bought the boat in 2006, years of leaking led to rot in the marine plywood forming the substrate of the tops of the hatches. I initially used Git-Rot to shore them up, and re-caulked with Life-Caulk.

Calif.Ted - yes, the teak planking is glued to plywood substrate. The framing is made of teak.

Cheechako - the lexan only forms the lens of each hatch. As I said to Calif.Ted, the framing is teak. Even the 20"x20" hatches with lexan are incredibly heavy for their size, hence me considering something similar to PVC siding trim boards laminated with epoxy and mechanical fasteners. I'm thinking the weight would be somewhere in the 50-65% weight range compared to the existing teak.

Bill O - beautiful example of what I was thinking: lightweight "plastic" to replace most of the teak frame, and use teak planking for aesthetics. I'll look into HDU...

I'm also considering covering the teak decking on top and possibly the sides with thin fiberglass cloth and epoxy, and finishing with 6-10 coats of Bristol Finish. Of course, I'd be afraid that after all that the hatches would weigh as much as they do now.

Edit: Seems that HDU is ~15 lbs / cubic ft, whereas teak is 41-55 lbs...

[MJH]

Originally Posted by Beausoleil

In another thread, someone had a problem similar to mine: what to do about leaking teak hatches:



I have the same problem - the teak hatches (four deck hatches and companionway and doghouse hatches) which need to be rebuilt. They're custom to my boat ('79 Formosa 51).

Do I rebuild them using teak? I could, but I'd have to maintain them more than I'd like in the future. But they sure are (were?) beautiful - these are pics from 10 years ago:




Do I replace them with a modern hatch? My wife has already vetoed that idea - maybe I should tell her she'll be in charge of future maintenance...

Because they're so damn heavy, I was contemplating rebuilding them using PVC - perhaps laminated (using fiberglass mat between layers for strength?, and then cladding them with thin teak strips (3/8" rather than normal decking thickness).

Two smaller hatches (20"x20") and the doghouse hatch have lexan lenses, but that shouldn't be a problem.

Would the laminating have enough torsional strength so that I could stand on the one hatch which is located under the mizzen boom? It's all teak decking on top similar to the companionway hatch pictured above, so I don't have to worry about scratching any lexan...

Would the weight savings from using PVC "outweigh" (pun intended!) the lesser strength of compared to that of teak? Would fiberglassing add enough additional strength without adding too much weight?

Glad to join this new topic from the other posting.

This is the response I got on having my teak hatch replacements made from another material in mid 2017:

"Here is my estimate for all 4 hatch frames, constructed of CNC machined and welded black ABS. Joints are solvent welded and box jointed, center spar included.

Cost: $4000. Lead-time: 3-4 weeks. This includes the design and programming we need to do in advance of building them. Black ABS will be very strong and resistant to weather and sun, and would not require paint or maintenance. Would you want us to put in all the holes for the hardware? There are a few options for the Plexiglas top covers if you want us to add those to the job.



Let me know what you think."

I never acted on it and now looking to just stay with teak that can be done locally. One of my concerns is that the hatch hole perimeters are not flat but rather surround the hatch hole upward that the hatch fits over...they essentially interlock somewhat like a tilde (~). Another factor is that the manufacturer is at some distance and I would have to transport each hatch to him to ensure proper measurement and return to wait for completion. Then there is the possibility they won't fit right the first time and another trip made...too problematic.

Looking forward to see if anybody has done this in the northwest, i.e. Port Townsend, WA.

~ ~ _/) ~ ~ MJH

[BenBowSirocco]

Ahh, well if the frame is salvageable in my opinion don’t use PVC. I have had poor experience glueing that stuff.

Quality ply is cheap and lasted 40 years.. saving weight could be done by using thinner plywood and planning down the teak.

I have had awesome experience with the high density PVC foams. Might be an option.

[coastalexplorer]

I made the lazarette hatch and companion way hatches for my project out of teak using dovetailed joinery and glued with west system epoxy.



For the lazarette the Teak cost $53 Cdn. The top of the hatch is a polymer sheet which I re-used the original; I don't recall paying much more for the teak used for the companion way hatch. The original was cracked so the replacement was $126 Cdn.

[Checkswrecks]

I know this is an interior use, but it's Home Depot Canberra Acacia luxury vinyl plank flooring. The planks are glued together with clear PVC cement meant for plumbing. After the adhesive dries for a couple of days they are fused into one piece.

The planking could be used as an inset in a fiberglass frame for exterior.



Below is 15" so is 3 planks wide:



You can see the tube of Gorilla Construction Adhesive in the corner, used to bond the planks to the fiberglass. It's a lot like 4200 when set.

Below is a piece of vinyl plank against a bulkhead for color comparison of the Acacia.



The only thing to be aware of is that where the panel is too long for one piece, the grains will not align at the ends. This won't be a problem with the hatch.


For the most part, the seams are so tight they are not visible. For those which are wide enough to be seen, fill the crack with a red umber acrylic from Michaels' Crafts and they disappear. There are also clear coats if you want to go high gloss.

[coopec43]

Since the teak appears to be cosmetic why not glue teak planks over a f/g hatch? Here is a hatch cover I made to protect the acrylic from UV. (I have a brick weight because I have yet to attach clips)

[Beausoleil]

Originally Posted by BenBowSirocco

Ahh, well if the frame is salvageable in my opinion don’t use PVC. I have had poor experience glueing that stuff.

Quality ply is cheap and lasted 40 years.. saving weight could be done by using thinner plywood and planning down the teak.

I have had awesome experience with the high density PVC foams. Might be an option.

My bad - I should have said PVC foam (the closed-cell, micro-bubble kind). I didn't mean the solid PVC akin to PVC pipe or pre-fabbed window frames...

I did a closer inspection of the hatches last night after I brought them home from the boat this weekend. I think I can re-use most if not all of the teak frames. The plywood substrate is gone, and the cosmetic teak planking is pretty thin, but I may be able to reuse some of it for one of the two larger hatches (25" x 26")...

I have some pvc foam board leftover from another project, but I'll look into the HDU as an alternative to replace the plywood...