Midship hatch removal and reinstallation

[Jim Walsh]

My midship hatch was weeping, just a few torturous drops, from one corner of the teak trim. It only occurred when lots of spray was flying. I figured I'd remove it, rebed it, and replace the gasket at the same time.
It was bedded in silicone (yuck) and I found gaps between the fiberglass and the teak trim. One quite large gap. I'm looking for advice on what to use to fill the gaps, and what to bed the frame with. I know butyl tape is popular but I'm wondering if 4200 might be best since the fastenings barely bite and the 4200 would supplement the mechanical fasteners.

[Gary H]

When I re-bed the hatch and all other deck fittings, I used butyl tape on fittings that were through bolted and 4200 on the hatch and any fittings with screws that were only threaded into the fiberglass. Butyl tape has no adhesive qualities and I thought should only be used under the compression of a through bolt and nut.

[Jim Walsh]

When I re-bed the hatch and all other deck fittings, I used butyl tape on fittings that were through bolted and 4200 on the hatch and any fittings with screws that were only threaded into the fiberglass. Butyl tape has no adhesive qualities and I thought should only be used under the compression of a through bolt and nut.

I think you're right. I've done some searching and it appears that 3M 4000UV might be best for this application. I still have to come up with something to fill the voids between the teak trim and the fiberglass.
The Bomar hatch is in great shape after 32 years. It has a deep caulking channel to lay out a substantial bead so I'm confident it will seal perfectly. Cleaning all the old silicone off the hatch is my job for tomorrow morning.

[Ron M.]

If the screws attaching the hatch frame aren't getting a good purchase the option would be larger screws,(if possible) or drilling out the screw holes and making an epoxy plug, then drilling the plug for the proper screw size. Be sure to remove any remnants of silicon by cleaning first with solvent. I used Boatlife to caulk the frame to the fiberglass 10 years back and have noticed no leaks.

[tjr818]

...Cleaning all the old silicone off the hatch is my job for tomorrow morning.

There are several Silicon Caulk removers on the market. I used one from Home Depot and was amazed at how well it worked.

[Jim Walsh]

...Cleaning all the old silicone off the hatch is my job for tomorrow morning.

There are several Silicon Caulk removers on the market. I used one from Home Depot and was amazed at how well it worked.

I had no idea. I just spent at least two hours removing all the silicone caulk from the hatch using a putty knife, a stainless wire brush, and lots of elbow grease. Oh yeah, I used a .30 caliber wire brush to clean the damn silicone out of the fastening holes in the hatches flange. It ruined a perfectly good cleaning brush but it fit the holes perfectly. I'll check out Home Depot tomorrow and use it on the fiberglass to insure I remove the silicone which I haven't managed to remove with my putty knife. Great tip, thanks.

I ended up filling the gap noted in my original post with 4000UV. It took an entire cartridge. It's real gooey, sticky, stuff. I'll be using it to bed the hatch also.

[Jim Walsh]

The hatch has been reinstalled. First I cleaned the mounting surfaces with a putty knife, a wire brush, and acetone soaked rags. I filled the gaping voids with the 4000UV and gave it a day to cure. Then I dry fit the hatch, which gave me the opportunity to mask the surrounding surfaces. After that it was time to lay a bead of 4000UV in the caulking groove. The tough part was placing the hatch into position on the first try so as not to smear my bead of caulk. I managed to get it damn near its final resting place....within a quarter inch or so. I ran all the fastenings in and went around only once to ensure they were just snug.
An hour later I removed the masking and it was "job done".

[Skylark]

Did you reinstall that hatch backwards?

[Jim Walsh]

Did you reinstall that hatch backwards?

No. This is the same orientation it was in when it left the the factory. I've had a boat with a midship hatch which opened aft. I felt the "exhaust" feature was overrated. I have found that the forward opening midship hatch, at least in my case, pumps a much greater volume of air below. Much appreciated in warm weather everywhere and a necessity in places like Bermuda. I knew I had the option of changing the orientation at this time but I was quite satisfied with the status quo.

[Skylark]

Getting ready tackle this job on Skylark. Almost finished rebedding the ports. Your pictures are helpful. Although, it looks like I will need to do some epoxy work to rebuild the cut out.

[Jim Walsh]

Getting ready tackle this job on Skylark. Almost finished rebedding the ports. Your pictures are helpful. Although, it looks like I will need to do some epoxy work to rebuild the cut out.

I'm glad the images were/are helpful. Good luck with your project.

[Steve Laume]

Getting ready tackle this job on Skylark. Almost finished rebedding the ports. Your pictures are helpful. Although, it looks like I will need to do some epoxy work to rebuild the cut out.

You may be pleasantly surprised as there were no voids around the hatches on Raven.

The biggest part of the job, for me, was prepping and painting the aluminum frame.

[Skylark]

I hope so. However, on Skylark it looked as if they used a chainsaw for the ports. Then filed the gap with polyester fairing. The plywood paneling was mulch.

[John Ring]

I hope so. However, on Skylark it looked as if they used a chainsaw for the ports. Then filed the gap with polyester fairing. The plywood paneling was mulch.

Tiara (CD36 #135) is the same way. The cutouts for the bronze ports are huge and rough. The interior panels are a mess.

John