Sliding roof hatch leak

Hello All,
I recently purchased a 1978 GB 42 Classic. During hard rain events water drips into the aft cabin from the sliding hatch. How does one remove the hatch to inspect and prevent the leaks ?
JLG

I don’t know how your sliding hatch comes off. We had a sliding hatch on our sundeck hardtop that leaked badly. I took it off, ground off the fiberglass rails and got rid of it. Probably not a good option for you.

Sliding hatch leak

I agree. I don’t think removal is an option.

Can you post some photos of the top and bottom?

Can`t remember how but the shipwright said removing the sliding hatch to the FB on my IG to repaint it was dead easy. Wish I could remember how, to help.

There are rails on the outer sides of the teak "sliders"...these are the thick pieces of wood running fore and aft which the hatch slides back on. You need to remove several small screws from the rails. Once the rails are removed you can lift the hatch lid straight off. NOW...the lid is likely not the source of the leak. If you look carefully you should find two weep holes on the bottoms of the sliders. These need to be kept clean and open otherwise in heavy rain the water can back up and seep into the hatch. I have a 1973 GB42 and had the same problem.

Isabella42, if you haven't already done so I would recommend joining the forum at IAGBO. Lots of good advice from veteran owners. There's also a pretty good Grand Banks Owners Group over on Facebook.

Have a Sunbrella cover made. Well worth it as it keeps water out and also protects the bright work. Pretty much standard on the Grand Banks.

The rails may have plugged weep holes. Others have found the water weeping through where the rails are fastened to the deck. Removing and rebedding is the final solution. where the rails meet the cross section is a ponding area that should have weep holes so standing water does not readily weep through joint mitre lines.

The rails are fastened by screws into the framing roof support. You should see where the rails have teak plugs inserted to cover the screws. once plugs and screws are removed the rails come off, then you can sikaflex bed them for another decade of leak free.

Add weep holes if none at where the rails meet the cross member.