Which brand of inspection hatch / inspection panel to buy?

TwoHooter

TwoHooter

Well-Known Member
Joined
6 Sep 2014
Messages
1,005
Location
marinetraffic.com MMSI 235116115
Visit site
I've done a search and can't find a direct answer to my question so I'm risking someone accusing me of duplication.

On our motorboat I need to create a watertight GRP bulkhead inside the starboard cockpit locker to prevent water from finding its way to the hole up through which comes the exhaust from the diesel-fired hydronic heater which sits below the locker in the lazarette. I want to fit an inspection panel in the new bulkhead so that it is possible to get easy access to the exhaust system. If all that confuses you perhaps this picture will help. BTW, after the watertight bulkhead has been made I will plug the further of the two drain holes.

The inspection panel/inspection hatch would ideally be about 300mm x 300mm but various different sizes and shapes would work.

I have found numerous candidates for the sort of inspection hatch I have in mind. For example:
http://www.force4.co.uk/department/...s-ventilation-lockers/inspection-hatches.html
I tried to reproduce other chandlers' search results without success. Bainbridge have a good selection for example.

Prices vary from less than £50 to nearly £200.

Here's my question: Does anyone have a view on which is the best quality hatch for this job? The hatch won't be directly exposed to weather but I want to know that it is truly watertight and I want it to last at least 20 years, preferably 30 or more. I'm willing to buy top of the range to achieve that but I've no way of knowing whether more money does buy better quality or whether I'll be just as well served by a cheap hatch as an expensive one. Believe me, there's a host of other things I can usefully spend this year's budget on if I don't have to buy an expensive hatch.
 
If you want top quality these are the people http://baileymarine.co.uk/categories/watertight_deckplates/products/bm200f.html They supply the RNLI quality usually comes with cost I bought a 150mm round threaded access hatch for my diesel tank made of delrin type material over 25mm thick beautifully made with a detachable handle I can access the interior of my tank in less than a minute a bit of a luxury at around £100 but the tank was always a nightmare in the past , you had to take the tank out to clean it.
 
I've got a couple of these - 'lid' is solid grp, held on with wing nuts on captive screws, and there's a soft rubber gasket between that and the bulkhead. My thinking is that something like this would let you make a fairly narrow width ring frame and a large lid for the best possible access.

fbulk hatch.jpg
 
sarabande said:
Why put a hatch in there ? It looks as if you have a frame already available, and a sheet of stainless cut to full size of the aperture and fastened by Dzus fasteners
Click to expand...
I am familiar with Dzus fasteners which were used for holding panels on one of my aircraft during my flying days. A purpose-made panel might work and would give me the largest possible aperture for maintenance.
sarabande said:
Woudl there be any issues of high temperature if you close off the exhaust part ?
Click to expand...
Good point. I don't think so - never detected any heat inside the locker when the heater is running, but I would like to be able to open the inspection panel either fully or partially, quickly and easily without using tools, in case we do need to let some heat out. We won't need to run the heater while at sea so the panel will always be shut (and the exhaust outlet plugged) before we cast off.
parbuckle said:
If you want top quality these are the people http://baileymarine.co.uk/categories/watertight_deckplates/products/bm200f.html They supply the RNLI quality usually comes with cost I bought a 150mm round threaded access hatch for my diesel tank made of delrin type material over 25mm thick beautifully made with a detachable handle I can access the interior of my tank in less than a minute a bit of a luxury at around £100 but the tank was always a nightmare in the past , you had to take the tank out to clean it.
Click to expand...
Thanks for the link - I am looking through their range now. I suppose my original question was whether you really do get a better quality hatch by paying more money.
anoccasionalyachtsman said:
I've got a couple of these - 'lid' is solid grp, held on with wing nuts on captive screws, and there's a soft rubber gasket between that and the bulkhead. My thinking is that something like this would let you make a fairly narrow width ring frame and a large lid for the best possible access.
Click to expand...
Very good solution but can it be opened quickly and easily? (see above)
 
Sorry 2H, forgot to reply - it takes about two minutes to get the cover off. Back on a bit slower. The wing nuts (not my choice, they were on the boat when I bought it) actually help much more than you'd think when spinning them off.

But you've probably finished the job by now anyway?
 
anoccasionalyachtsman said:
But you've probably finished the job by now anyway?
Click to expand...
Chance would be a fine thing. Have spent literally hours trying to buy a watertight hatch that will fit the space. No success unless I pay Mr. Bailey half a UK Boat Unit, which seems a fair price given the crud I've been looking at, but is outside my budget. BTW, even Bomar hatches are stated unequivocally to be " Fully gasketed (but not watertight)". The only rectangular or square hatch I can find that is reliably watertight would be an IP67 electronics enclosure with the back cut off.

Current plan is this: (1) Make a new properly glassed-in frame; (2) screw a panel to that, using Arbokol 1000 (or, if I'm feeling parsimonious, my existing tube of un-branded Butyl Rubber) as a sealant; (3) Cut a circular hole in the panel and seal in one of these: http://www.tcschandlery.co.uk/viking-marine-lock-in-deck-plate-ptl8-white-286mm-dia/p11069. The Viking products seem reasonably watertight. If we sink you will have the satisfaction of knowing I was wrong about that.

The circular deckplate is easy to remove for inspection and if necessary to let heat escape when the furnace is running (we just don't know at the moment whether that is an issue or not), but it isn't big enough to make it easy to replace the furnace exhaust silencer. When that time comes we can remove the panel and have the same amount of access that we do now.

That's the plan.
 
Sounds most sensible. I don't think that I've used one of the Viking hatches, but like you have my doubts about most of the others. I've also got doubts about my buoyancy tanks - it being a racy sailing boat both have various strings going through them, and sealing those isn't possible. If you're in the Solent we should probably watch each other's backs.
 
You must log in or register to reply here.

Share this page

Top