Temporary exhaust hose repair

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Pavalijo

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We are working our way south this year and after more hours motoring than we had hoped, today I discovered that the exhaust hose has been rubbing against the engine blower fan in the transom void.
We are very lucky that it had not worn right through - an area the size of a 20p coin is very thin.
Ideally we need to use a weather window on Tuesday/Wednesday to progress, and I want, therefore to effect a temporary repair.
My initial thought is to get a 300mm piece of hose, slit longitudinally, liberally apply silicone sealant (is that ok at temperature?) and clamp the hose around the affected area with jubilee clips - needs to last a couple of months only before I get the whole length replaced.
Any thoughts appreciated
Paul
 
Without knowing the exact circumstances, I'd be tempted to
1) do the protective 'bandage' with a bit of split hose and Jubilee clips as you describe,
2) skip the silicone sealant
3) keep an eye on the repair in use just in case any leak develops, and if so how much of a problem it is
4) order a new length of hose to be delivered to your next planned port of call. Why wait a couple of months, for goodnes sake?
 
Proposed improvised repair sounds reasonable to me. Not sure the silicone is 100% necessary, but it can't hurt. Should be no problem with temperature - a water-cooled exhaust hose shouldn't be all that hot in the first place, but in any case silicone rubber is sometimes used for baking trays and the like in domestic ovens.

If you can get it, a short length of stainless pipe with an OD matching the ID of the hose would make an even better repair; could be regarded as permanent. Cut the hose, insert the pipe, add a hose-clamp or two each side.

Pete
 
prv said:
If you can get it, a short length of stainless pipe with an OD matching the ID of the hose would make an even better repair; could be regarded as permanent. Cut the hose, insert the pipe, add a hose-clamp or two each side.

Pete
Click to expand...
I now carry two ss inserts plus a length (1ft ish) of exhaust hose after getting caught when crossing Biscay by a blown exhaust hose.
My fix at the time was a patch made from a split length of domestic water hose, bound on by lots of self amalgamating tape, then duck tape, then about five hose clips.
 
LittleSister said:
Without knowing the exact circumstances, I'd be tempted to
1) do the protective 'bandage' with a bit of split hose and Jubilee clips as you describe,
2) skip the silicone sealant
3) keep an eye on the repair in use just in case any leak develops, and if so how much of a problem it is
4) order a new length of hose to be delivered to your next planned port of call. Why wait a couple of months, for goodnes sake?
Click to expand...

+1 except I'd definitely go for the sealant. It needn't be silicone, or even particularly temperature-tolerant, because, as prv writes, water-cooled exhausts run at quite low temperatures: less than 50C. Gas leaks are the biggest risk because they can kill you without obvious warning. Although diesel emissions are quite low in CO, there are lots of other not-quite-so-nasty nasties. On the other hand the hose seems not actually to be perforated.

Hourly checks that all is well would be prudent.

A section of steel tube is the best bet. Needn't be stainless if a temporary fix.
 
prv said:
Proposed improvised repair sounds reasonable to me. Not sure the silicone is 100% necessary, but it can't hurt. Should be no problem with temperature - a water-cooled exhaust hose shouldn't be all that hot in the first place, but in any case silicone rubber is sometimes used for baking trays and the like in domestic ovens.
Click to expand...

Also used directly on engines...RTV silicon.

If you can get it, a short length of stainless pipe with an OD matching the ID of the hose would make an even better repair; could be regarded as permanent. Cut the hose, insert the pipe, add a hose-clamp or two each side.

Pete
Click to expand...

+1 That's good advice Pete.
 
Many thanks for the reassurance and good tips.
I will try and source steel pipe as suggested - and will use a full reel of self amalgamating tape as well as silicone to get the best CO tight seal as I can - it is not yet perforated but very close to being so. We do have a CO alarm on board.

If the stainless steel pipe could be regarded as a permanent repair then that is good, as the hose looks quite new ( but will check internal condition whilst having the opportunity.

Reason for waiting 2 months - not sure we will get the opportunity to sort it properly before then. We are in transit currently South Wales and wanting to be in Southampton for the boat show and to end the season - but needing to be home for a few weeks from mid July. We might get the opportunity but just might not. Had the reaction here been different then we would have delayed departure from here for as long as it takes, but prefer to keep going.

Thanks again
Paul
 
Pavalijo said:
Many thanks for the reassurance and good tips.
I will try and source steel pipe as suggested - and will use a full reel of self amalgamating tape as well as silicone to get the best CO tight seal as I can - it is not yet perforated but very close to being so. We do have a CO alarm on board.


Paul
Click to expand...

Even stainless steel is not necessary. Mufflers, water traps and goose necks etc are plastic

Vetus do a range of plastic exhaust hose connectors, both straight and angled. in sizes to fit common exhaust hoses. One of these could be used as a permanent repair!
( you will find that off cuts of stainless steel tube only come in two sizes: too large and too small)

See This page http://www.vetus.com/exhaust-systems/exhaust-hoses.html?p=2 and the followig one.

Or Vetus Direct http://www.vetusdirect.com/exhaust-systems/slvbg40-150k-1938617406/


SLVBR40K.jpg
SLVBG50K.jpg
 
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lpdsn said:
I carry a roll of this for just such an eventuality.

http://www.rescuetape.co.uk/Rescue-Tape/welcome-to-rescue-tape-uk

I don't know if it actually does what it says on the box as I've never had to use it (yet!). Bought it from Seascrew.
Click to expand...

+1

If you have good access or can remove the hose, then a few wraps of self-annealing / self-amalgamating tape would be a permanent fix. I have used my roll a couple of times and it does the business.

Richard
 
I had a similar issue with a rubber raw water hose. I used sikaflex to fill the chafe and then wrapped with self-amalgamating tape.
 
prv said:
Proposed improvised repair sounds reasonable to me. Not sure the silicone is 100% necessary, but it can't hurt. Should be no problem with temperature - a water-cooled exhaust hose shouldn't be all that hot in the first place, but in any case silicone rubber is sometimes used for baking trays and the like in domestic ovens.

If you can get it, a short length of stainless pipe with an OD matching the ID of the hose would make an even better repair; could be regarded as permanent. Cut the hose, insert the pipe, add a hose-clamp or two each side.

Pete
Click to expand...

Silicone sealants are a different chemistry, most of them are only good for reasonably low temperature use.
There are some high temp sealants, always wise to check the use temp on the data sheet :)
I use this one if I have temperature worries
https://www.dowcorning.com/applications/search/default.aspx?R=396EN
 
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prof pat pending said:
Silicone sealants are a different chemistry, most of them are only good for reasonably low temperature use.
There are some high temp sealants, always wise to check the use temp on the data sheet :)
I use this one if I have temperature worries
https://www.dowcorning.com/applications/search/default.aspx?R=396EN
Click to expand...

But there are no temperature worries. As said, wet exhuasts run at less than 50C. If that temperature is exceeded, it's because something in the seawater circuit has gone badly wrong, in which case the hose being bodged will likely fail, anyway.
 
I carry self amalgamating tape with emergency repair in mind, but wanted to do something a little more robust.
Thanks for the pointer to Vetus which will hopefully be the permanent solution.
The other helpful tips suggest self amalgamating tape plus silicone and secured inside a short length of hose fastened by jubilee clips should do the job.
Will order 2 of the Vetus connectors and carry one as a spare!
 
Having owned a boat with an Isotemp Calorifier which would start to leak at the rubber gasket around the end plate carrying the imm. element every time we crashed off a high wave, I have had considerable experience of trying to use sealants at relatively low temperatures, my experience has been that ordinary silicone sealant have very limited usefulness, Sikaflex was recommended for the job by Vyv Cox and would hold around the gasket for a couple of years and Technicqill 300 degree 'liquid gasket' sealant appeared to be capable of lasting a bit longer.
Of course the final solution was to dispense with showy thin Italian steel and invest in a proper traditional British made Surecal.
 
macd said:
Beg to differ: that's clumsy. The permanent solution is a new length of hose, routed (and, if necessary, constrained) to avoid chafe. The fewer joins, the better.
Click to expand...

It's a very neat repair compared with some of the suggestions in the thread and will, without doubt, last until the time eventually comes to replace the whole hose.
 
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