westerlylad
Active Member
Morning all. Any chance that I'll be able to re-use the existing gaskets if I remove manifold?
DV20 Exhaust manifold gaskets
- Thread starter westerlylad
- Start date
Neeves
Well-Known Member
I have re-used ours without issue but I have damaged them and I have bought a sheet of the appropriate gasket 'material' (A4 sheet) and I have cut my own.
Jonathan
Jonathan
westerlylad
Active Member
Many thanks Jonathan. I think I'll keep my fingers crossed that mine are okay when I take the manifold off. If not, I'll have a look for some gasket material. On another subject, I've just been looking at my exhaust bend and there is a fine split forming at the lower weld (the underside of the bend). The rest of the elbow appears okay and it is a sold lump of metal with no rust. Have you any thoughts about the possibility of a successful repair, either a weld or some epoxy? (Can you sense I'm running this boat on a limited budget?)
Colin.
Neeves
Well-Known Member
I'd not think epoxy would work, too warm.
If you weld try it, you have nothing to lose.
I had an elbow with a split in it, an obvious split - but it actually did not leak.
I have found that the original gaskets actually lost a long time, if you are careful when you take the elbow off. I bought the spare gasket material after I broke one and I have only made one gasket in 20 years. The major problem I have found is internal corrosion exacerbated because I clean the elbows with acid (cannot actually think how else to do it).
For what they are they are inordinately expensive and now that I think about the engine - the elbow is the most expensive item I buy.
Jonathan
westerlylad
Active Member
Thanks again for your reply Jonathan. I think I'll bite the bullet and just order a new elbow. The thing I cant understand is what causes this type of split in a substantial (and expensive) metal part. I don't see any signs of major corrosion either inside or outside, just the fine split forming along the underside seam. Mine was leaking unfortunately and will presumably get worse from here on. I understand the there is a stainless steel alternative for this part, so I'll have a look at that option too. Cheers. C.
emmalina
Well-Known Member
Used mine twice with no problems but did give them a lick of hylomar last time !
Neeves
Well-Known Member
There have been a few threads, sorry there have been a lot of threads, on exhaust elbows and a few of them have made mention of stainless replacements. I have no experience so cannot comment - but summarising my recollections - people seem happy with stainless replacements
Try and have a search using the search function here on YBW and then maybe start a new thread on Volvo exhaust elbows and stainless replacements. If you have the time and don't want to use your yacht tomorrow, or next week, it might be worth investing some time in deciding if you should spend your money on a replacement (from Volvo) or going the stainless route. Normally you can source a Volvo replacement from stock (or you can here in Oz).
I suspect your elbow might have had a flaw from new but it is impossible for you, or anyone, to check every component on a yacht and some things slip through. Possibly use exacerbated your flaw to the point where it becomes an issue.
Jonathan
emmalina
Well-Known Member
Neeves
Well-Known Member
The advantage of use of a stainless elbow has never been explained/confirmed (or I do not recall it being reported).
Most elbows cause issues because the elbow becomes blocked with a carbon rich or carbon impregnated blockage of calcium carbonate or hydroxide. This deposit can be removed with acid. Longer term the Volvo elbow also corrodes and eventually leaks - and at this point it has failed completely - an acid wash only makes the corrosion worse.
Why the blockage occurs in the first place is not clear but maybe due to a combination of the exhaust gases, the sea water AND the presence of the Fe from which the elbow is made.
I have seen no mention that the stainless in any way retards the calcium deposit. I can see that if the welds are made correctly in a stainless elbow that corrosion might be reduced or minimised, prolonging elbow life, but I have seen no comment that a stainless elbow reduces the blockage.
Jonathan
Most elbows cause issues because the elbow becomes blocked with a carbon rich or carbon impregnated blockage of calcium carbonate or hydroxide. This deposit can be removed with acid. Longer term the Volvo elbow also corrodes and eventually leaks - and at this point it has failed completely - an acid wash only makes the corrosion worse.
Why the blockage occurs in the first place is not clear but maybe due to a combination of the exhaust gases, the sea water AND the presence of the Fe from which the elbow is made.
I have seen no mention that the stainless in any way retards the calcium deposit. I can see that if the welds are made correctly in a stainless elbow that corrosion might be reduced or minimised, prolonging elbow life, but I have seen no comment that a stainless elbow reduces the blockage.
Jonathan