Hose conection

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flylhp

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Hi
Has anybody got any tips for connecting a hose on my water intake the filter connection is 16mm and the impeller housing is 19mm will 19mm hose clamp on 16mm

Flylhp
 
Why not fit an adaptor? You'll need two short lengths of hose, one 16mm and one 19mm but it's less likely to leak. Either your local chandlery or from the likes of Tek Tanks ( here
 
Please excuse my ignorance, but what is self amalgamating tape and where can I get it?. It sounds like something that I should have in my toolbox.
 
Alternatively, use 16 mm. hose which will stretch to 19 mm. after immersion in hot water. I had a similar problem with my cockpit drains. It worked for many years and the boat never sunk. (Tho' I've now removed the problem.)
 
[ QUOTE ]
Please excuse my ignorance, but what is self amalgamating tape and where can I get it?. It sounds like something that I should have in my toolbox.

[/ QUOTE ]It's a tape that when wrapped around something and itself will weld itself to itself (amalgamate) and form a thicker tape.

It is oftern sold in car shops and comes with a protective tape that is applied first. Think along the lines of a leaking radiator hose.. Wrap the protective tape around the leak to provide a strong base for the amalgamating tape which is applied next by wrapping with an overlap.

It's rather like a chemical shrink wrap if that makes it any clearer ??
 
Self amalgamating tape.....

... does what it says on the tin.

Stretch as you wrap and it forms a solid mass of material.

Sold by swindleries world wide. More savvy buyers use the local electrical wholesaler and get 10 rolls for the price of one marine version.
 
I wouldn't try and clamp 19mm hose onto a 16mm fitting, as you may not get a solid fit.

However, faced with a similar problem, I used the smaller hose to the smaller fitting, larger hose to the larger fitting and overlapped the larger hose over the smaller hose, which was a tight fit. Making a long overlap and using some sealing tape or sealant will make sure the join is permanent and fully waterproof.
 
Dont bodge the job,go to your local plumb centre and you should be able to get a copper reducer that will do the job.If you ask for a "yorkshire" fitting they have ribs that hold the solder, this will give the jubilee clip something to "bite" on.Get a small screwdriver and lever the solder out of the recess so that it doesnt come out later.If the small end of the reducer is not big enough solder a coupling on and use that.If you have a plumber friend show him the 2 pipes and he will know what you want. Dont forget to leave enough pipe for the hose to grip.Thats why I suggest a coupling at the end.
 
GULP!

I can't believe the standard of advice you're getting!

Not wishing to get at anyone, but.....

This is your raw water intake - if it falls off, either the boat fills with water, or the engine overheats, or both together - no? There are times & places for bodges, but this isn't one of them (IMVHO). You *need* the correct hose for each end, with the appropriate adaptor between them (can't cost more than a fiver, surely??) and decent hose clips. The hose must not be too tight or too loose a fit on the nipple, because it will either split or fall off with engine vibration / heat over time (this assumes the hose nipples are cast / moulded in, and cant be changed). One piece of hose shoved up another may hold forever, or they may just decide to come apart one day.

Bodge the galley sink drain, if you must, but not this one /forums/images/graemlins/crazy.gif

Andy

(must buy decaff...... /forums/images/graemlins/grin.gif)
 
I agree misterg.If he gets a "yorkshire" type coupling either end of the reducer its as good as a cast coupling,thats if he cannot get the right coupling,but the hoses need to be a good push on fit ,with the raised areas,for holding the solder, he has something for the jubillee clips to fasten onto. I used these on my 40psi hot water system on my previous boat with no trouble.but you must lever the solder thats not used on the joint out of the inside of the couplings as previously suggested.
 
GULP! and WEEP! from me too.

To the original poster, I would suggest doing it (or any similar below the waterline job leading to the sea) properly for the reasons misterg gives. However, with small diameters and only a small difference in hose size it may be difficult to get something straight off the shelf (I have not checked).

I am not in the UK but I find the best source of fittings for such jobs are the companies that make up hoses for industry as they have a wide range of 316 ss fittings available and cheapish as well in the smaller sizes. There are plenty of them here and they will put the required bits together in front of you.

If standard fittings cannot be sourced from them then an engineering shop will turn you up an adapter with hose tails each end out of 316 ss bar very quickly.

I suggest 316 ss as the fittings will be permanently marked as from that material, whereas with "bronze?" one is never sure unless a certified trail exists. Glass reinforced plastic is also fine if from a known manufacturer but may be difficult to get the size change you want. I find ss is just easier in all these ways but if using it use a thread sealing paste (not tape) on any threads or else they will likely weep slightly.

Given the small hose diameters you may lose quite a bit of flow area through the adapter fittings - while likely not a problem on the suction side of your raw water pump, assuming it is the normal impeller type, after fitting I would double check the cooling water flow through the engine just to be sure.

John
 
Just a small point here guys but it seems to me that you should really use the same pipe dia all the way through the system. If the impeller inlet is 19mm (3/4") then you should be running 3/4" all through and not restrict the flow from the sea-cock by using 16mm (5/8").

FWIW I would look at changing the filter or filter connection for a 3/4" version.

I'm in the middle of changing one of my clubs boat engines from a Yanmar 3GM30 to the new Yanmar 3YM30 - on the old 3GM the impeller connection pipe was 1/2" but the new engine is 3/4". So I have had to replace the sea-cock and pipe work so that I don't get to much suction on the pipe because the pump wants more water than the hose can deliver.

Peter.
 
[ QUOTE ]
you must lever the solder thats not used on the joint out of the inside of the couplings

[/ QUOTE ] Why not use "end feed" fittings in the first place.

I have some doubts about the idea to use plumbing fittings any way. Firstly I dont think the raised solder ring on Yorkshire fittings will make a good anchor for the hoses. Certainly not as good as the "barbed" rings on a proper hose tail. Secondly while the OD of a 15mm fitting may be about the right size for the 16mm bore hose although they are actually approx 17.5 mm od. I don't think you will find a sensible size for the 19mm hose as the next size up in plumbing fittings is 22 mm and those'll have an OD of approx 24.5mm You can get a "fitting reducer" that fits onto 15mm pipe at one end but is plain 22 mm OD the other, which you may get softened 19mm hose on to. A third objection would be that you would not be able to get double hose clips onto the fittings. Fourthly all this domestic stuff is very thin walled.

If you must use domestic fittings the use a bit of 22mm pipe, which you might get a softened 19mm hose onto, a 22 to 15 reducer and then a short length of 15mm pipe beefed up with a straight 15mm end feed coupling perhaps.

I fear you are just moving from one bodge to another though.
Far better to change one of the hose tails so that they are both the same if that is possiblle or get a reducing connector with proper hose tails.

My favourite "bodge" would be to put a piece of non-reinforced plastic hose on the 16mm tail and then fit the 19mm hose on top of that and secure with 2 clips. I really dont think that would let you down.
 
Take your point Andy, and of course you're right in what you say and I agree that it is the "proper" way to do it.

However, in my very humble opinion, using a piece of thinner hose on the smaller fitting and fitting the larger hose over it with a suitable overlap, with the inner hose covered in 5200 and the outer "join" sealed with 5200 and taped, with a couple of hose clips at the fitting is never going to come apart and offers at least as much if not more resistance and flexibility to engine vibration.

Not arguing with you, but genuinely interested in where you see the potential weakness of this compared to the potential weakness of a hose clamped to a fitting.
 
Just a small point here guys but it seems to me that you should really use the same pipe dia all the way through the system

Isn't that exactly what he is saying he wants to do???

He asks if 19mm hose will clamp on 16mm hosetail which to me means he wishes to run 19mm from pump to filter.

However, I think some realise that at the 16mm hosetail end on the filter it may likely not be easy to replace the 16mm hosetail with a larger one (unless the 16mm hosetail is a male reducing one or already in a reducing bush or similar which could be removed and the larger hosetail screwed in). In which case a short length of the smaller size hose on the existing filter hosetail to the adapters or whatever to the larger hose is quite satisfactory and cheaper than changing the filter, etc.

John
 
Vetus make an adaptor in plastic, for exactly the job you wish to do, it's a multistep adaptor, which you cut at the suitable joins, you will understand when you see it. It has exactly the right sizes you need. No bodges!
 
Sorry I misunderstood. What I was saying is that he should change the 16mm fitting to 19mm. I know Vetus do them because I've just bought some?
Peter.
 
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