Sealing heating pipes through narrowboat engine bay bulkead

[Telstar]

Hi All,

I was looking around my engine bay today and noticed the heating pipes, from the eberspacher to the radiators, passes through the engine bay bulkhead with little in the way of sealing.

 

Mine are of particular concern as they pass through only a few inches above the bottom of the bilge.

I'm thinking of dismantling the pipework and fitting a couple of (15mm) cable glands.

What is the normal practice to attain a good seal here?

 

Andy.

[PD1964]

Is it the standard 15mm speed fit pipe?

If you don’t want to cut basically lots of a good flexible waterproof sealant if you want a simple solution.

 

Edited May 22, 2021 by PD1964

[Tony Brooks]

I would probably cut the pipes and fit a par of 15mm bulkhead connectors with sealing washers on both sides. They will probably be compression so if you are using plastic pipe make sure to use metal pipe imserts.

[blackrose]

1 hour ago, Telstar said:

 

 

Mine are of particular concern as they pass through only a few inches above the bottom of the bilge.

 

 

Whoever has done that has compromised the watertight integrity of the bulkhead.

 

Don't try to seal them in that position, it's a bodge. You should fit a couple of bulkhead fittings higher up, at least 18" from the floor and fit the pipes though them. Seal the old holes ideally by getting them welded up, but a good second option would be a small steel or aluminum plate stuck on with Stixall or another good PU sealant. If that's what you do, abrade both surfaces first and clean them with a bit of white spirit on a clean cloth to make sure there's no dust or grease.

[Tracy D'arth]

4 minutes ago, blackrose said:

 

Whoever has done that has compromised the watertight integrity of the bulkhead.

 

Don't try to seal them in that position, it's a bodge. You should fit a couple of bulkhead fittings higher up, at least 18" from the floor and fit the pipes though them. Seal the old holes ideally by getting them welded up, but a good second option would be a small steel or aluminum plate stuck on with Stixall or another good PU sealant. If that's what you do, abrade both surfaces first and clean them with a bit of white spirit on a clean cloth to make sure there's no dust or grease.

Glue as part of a watertight hull? I don't like that idea.

 

  I would use big gauge nut and bolt with steel and rubber washers both sides.

[blackrose]

16 minutes ago, Tracy D'arth said:

Glue as part of a watertight hull? I don't like that idea.

 

  I would use big gauge nut and bolt with steel and rubber washers both sides.

 

Rubber washers as part of a watertight hull? I don't like that idea.

 

"Glues" are used to hold aircraft together and seal all sorts of watertight systems. Perhaps you've never used industrial PU adhesive/sealants. 

 

I wouldn't recommend it on the outside of a hull although I have temporarily fixed a hole in the hull of a steel dinghy with Sikaflex and a piece of ply.

 

Stixall goes off like rubber and when I've used it to stick ply to bulkheads to mount things on (instead of drilling screwholes) after 24 hours though you'd need a hammer and chisel to get it off.

[Tracy D'arth]

We agree to differ.

 

Aircraft don't have oily diesel engines.

 

I use lots of polyurethane adhesives.  Still to find a surveyor who would pass a boat where the hull water tight integrity depended on any glue. 

[Chewbacka]

6 minutes ago, Tracy D'arth said:

We agree to differ.

 

Aircraft don't have oily diesel engines.

 

I use lots of polyurethane adhesives.  Still to find a surveyor who would pass a boat where the hull water tight integrity depended on any glue. 

GRP often used to make ocean boats are basically glue and glass fibres.  Seems to be reasonably waterproof.

[MartinW]

Just an idle thought, but shouldn't the circs be in 22mm? Also if you lift the pipes up higher that might make a potential airlock?

[Telstar]

Hi Martin,

 

There's only 3 small radiators on the heating side is 15mm is fine for the radiator run.

There would be plenty of scope to raise the point of entry through the bulkhead, without creating an airlock issue, but I think I'll just make a 100% sound job of sealing the pipes where they are.

Thanks to everyone for the sealing suggestions. I'll have another look and let you know how it goes.

 

Andy.

[jake_crew]

Jet aeroplanes run on paraffin.  That's quite oily.