Bilge Inspection Holes

[Richard10002]

A few weeks ago I had a few leaks from my Truma hot water tank, which coincided with the boat listing quite a bit to port, (same side as the tank). I dont have any inspection hatches so used an 86mm hole saw to cut a hole at the bottom of a wardrobe close to the stern steps. Quite full of water, pumped as much as I could see out with a wet and dry vacuum, and called it quits.

 

The boat is almost level again, but I wouldnt be surprised if there is still some water down there, so I started thinking about proper inspection hatches.

 

Came across a video by "Journeys with Jono" where he was considering a similar issue and used a "Cavity Master Kit" by "Super Rod"

 

https://super-rod.co.uk/cavity-master/

 

However, all the "Where To Buy" places dont seem to stock it anymore, so I wonder if it's been discontinued. Does anyone know anything about it, where I might get one, or is there an alternative.

 

If I cant get hold of one, I'll go back to plan B, and cut some bigger holes and make some covers.

 

Here's Jono's video, (from about 8mins 45 secs to the end) :

 

 

 

[ditchcrawler]

1 minute ago, ditchcrawler said:

[magnetman]

If you don't have to walk on it then kayak deck hatches would work. No special cutter needed just a jigsaw or a normal holesaw. 

 

https://www.ebay.co.uk/itm/314031567566?hash=item491dbd72ce:g:-gIAAOSwf5Vio0Hw&var=612707360099

 

 

Edited January 18, 2023 by magnetman

[Jon57]

If you have room and a router I'd use a Trend routerbout. Someone will post a link I'm sure. I'm not that clever 😁

[koukouvagia]

 

Another way of making inspection panels is like this.  The floor board next to the wall along the whole length of the floor can be removed in small sections.

[Bee]

Thing is with boats is that no matter who builds them or how sophisticated and wonderful the fit out is the fact is that they are mild steel boxes not much different than your average skip in construction and the bit beneath the floor should be accessible throughout the whole boat - or as much as is reasonably possible. Any damp down there can turn to rust and nasty wet scale and a favourite place for that to form is along the join where the side meets the bottom. I would encourage anybody who is having a boat built to have really good access to the important stuff. very little on a boat is 'fit and forget'

[Tony Brooks]

10 minutes ago, Bee said:

Thing is with boats is that no matter who builds them or how sophisticated and wonderful the fit out is the fact is that they are mild steel boxes not much different than your average skip in construction and the bit beneath the floor should be accessible throughout the whole boat - or as much as is reasonably possible. Any damp down there can turn to rust and nasty wet scale and a favourite place for that to form is along the join where the side meets the bottom. I would encourage anybody who is having a boat built to have really good access to the important stuff. very little on a boat is 'fit and forget'

 

That basically means the floor goes down AFTER the bulkheads, fixed furniture and partitions, so whole floor areas can be lifted like many GRP Cruisers. I would comment on koukouvagia's  post. A fine idea but not so much of the floor is sheets of ply, OSB or worse. Those need more work to install an under floor lip to support the floor section that has been cut out and replaced. That is not difficult with wood offcuts screwed half under the existing floor glued and screwed in place by countersunk screws.

[rusty69]

5 minutes ago, Tony Brooks said:

 

That basically means the floor goes down AFTER the bulkheads, fixed furniture and partitions, so whole floor areas can be lifted like many GRP Cruisers. I would comment on koukouvagia's  post. A fine idea but not so much of the floor is sheets of ply, OSB or worse. Those need more work to install an under floor lip to support the floor section that has been cut out and replaced. That is not difficult with wood offcuts screwed half under the existing floor glued and screwed in place by countersunk screws.

That is the method I used on our boat. 

[Tony Brooks]

Just now, rusty69 said:

That is the method I used on our boat. 

 

And the one I would use if I was fitting out my own boat, but it is more time-consuming and its benefits are not as obvious as fancy wooden interior trims etc. That is why it will remain mainly a DIY practice in narrow boat fitting.

[rusty69]

14 minutes ago, Tony Brooks said:

 

And the one I would use if I was fitting out my own boat, but it is more time-consuming and its benefits are not as obvious as fancy wooden interior trims etc. That is why it will remain mainly a DIY practice in narrow boat fitting.

And even more work if you have a partitioned bilge, a keelson and a 70ft boat such as ours is. 

Edited January 18, 2023 by rusty69
spelling and grandma

[Martin Nicholas]

Barry Wren fitted access hatches along the length of the boat, in the corridors. This is how he ballasted boats once they were in the water and thus got it right every time. It's been useful to get under there on many occasions since.

[Jon57]

3 hours ago, Jon57 said:

If you have room and a router I'd use a Trend routerbout. Someone will post a link I'm sure. I'm not that clever 😁

 

[Alan de Enfield]

1 hour ago, Tony Brooks said:

................so whole floor areas can be lifted like many GRP Cruisers........................

Whilst we have access to the engines via 'under the stairs down to the rear cabin, much easier access is avilable by lifting the floor panels.

 

View from below :

 

The floor panels sit on joists which in turn sit into joist hangers, a section, or the whole floor, can be lifted to give easy access to both engines.

 

 

 

 

 

[robtheplod]

4 hours ago, magnetman said:

If you don't have to walk on it then kayak deck hatches would work. No special cutter needed just a jigsaw or a normal holesaw. 

 

https://www.ebay.co.uk/itm/314031567566?hash=item491dbd72ce:g:-gIAAOSwf5Vio0Hw&var=612707360099

 

 

This is what i used, although black. I too was interested in the Journey with Jono solution, but its not widely available (not made anymore) and its quite expensive. I have two of these directly above 'joists' below so i can see in two compartments with each hatch. 

[Puffling]

2 hours ago, Jon57 said:

 

It's still quite pricey, but if you already have the router a useful addition to the tricks it can do, I'm sure.

[Jon57]

1 minute ago, Puffling said:

It's still quite pricey, but if you already have the router a useful addition to the tricks it can do, I'm sure.

Cheap one on eBay sometimes. Got one to do 22 mm for sale on gumtree brand new unused for £25

[blackrose]

I just drilled 4 big holes and connected them with a jigsaw. My 2 layers of broken concrete ballast slabs were too big to get out of the hole so I used a lump hammer and cold chisel to break them up (wear eye protection). If you can cut the floorboard out with the jigsaw at a 45 deg angle sloping in then you can just place the hatch cover back over the hole afterwards and it will be self-supporting. Or just use a couple of lumps of wood and spacers of the right height sitting on the baseplate to support the cover.