Unusual valve thread size for my inflatable

[Refueler]

I have a two man inflatable based on the Soviet 2 man Military .... bought it many years ago in Tallinn ....

The dinghy is fine ... but valves are now failing ...

They are of Boston Valve design with a main body screwed into dinghy - a diaphragm rubber disc one way seal - then a centre plug that screws in to double seal.

The main body thread size (diameter across threads) is 29mm. All the ones I find online are either 20 or 23.9mm. Anyone any ideas - (I don't want to start cutting and replacing valves !!)

 

[PetiteFleur]

I have a small Campari inflatable, made of Hypalon I believe and they have a similar valve as Refueler but are made of brass with a small thread. I cannot find an adaptor for a pump... It's on ebay at the moment.

 

[Refueler]

The design is a standard Boston Valve - used by many brands ... but mine has the larger unusual thread diameter.

It has crossed my mind whether possible to just replace the rubber disc diaphragm in the centre .. as the body of the valve appears ok.

 

[Refueler]

mmmm today decided to swap valve bodies between the two chambers .... appears that its not valve problem.

So squirty bottle of soapy water ... pump up dinghy and start squirting ..... BINGO. Same as my Avon - a small hole in the bow - but this one is a little bigger ... about 1 - 2mm slit. So no chance with fluid. This needs a patch.

Out with my kit ..... plenty of patch material - but glue hard and unusable. SVB order now in for Glue and Gummipaint ......

 

[Metalicmike]

Keep a pot of Silicone Grease handy and smear it on the diaphragm and seals before you inflate it.

 

[Refueler]

Keep a pot of Silicone Grease handy and smear it on the diaphragm and seals before you inflate it.

I use never dry silicon spray .... we use it out here to stop car / house doors from sticking in the cold winters.

 

[Bleakonyv]

Sounds like a tricky valve thread size issue. I had a similar headache with an inflatable, and ended up 3D printing a custom adapter to make it work. If you can’t find an exact match, maybe try looking at industrial suppliers or plumbing fittings—sometimes you’ll find obscure sizes there.

 

[DinghyMan]

Sounds like a tricky valve thread size issue. I had a similar headache with an inflatable, and ended up 3D printing a custom adapter to make it work. If you can’t find an exact match, maybe try looking at industrial suppliers or plumbing fittings—sometimes you’ll find obscure sizes there.

It could be the bodge size M29 x 3 which seems to be a favourite of manufacturers who want you not being able to find any spares