Slowly going through maintenance on the Space Sailer. Want to check the raw water impeller on the VolvoPenta 2001 engine. I would like to replace the water pump gasket, and can make one easily, but I have no idea what thickness gasket material is required.
Whenever I have checked out boats, the raw water pump always seems to have a salt encrusted rim. Looks like this gasket, or lack thereof, is a common problem.
Any idea what thickness to buy?
Have you had a look at it to confirm there is a gasket or is it an o ring ? If it does have a gasket the thickness may be important to the cover plate impeller clearance. To thick and you will lose pump efficiency. I usually measure the housing and impeller heights before making a gasket, that is if I have to make one.
Select to expand quoteJolene said..
Have you had a look at it to confirm there is a gasket or is it an o ring ? If it does have a gasket the thickness may be important to the cover plate impeller clearance. To thick and you will lose pump efficiency. I usually measure the housing and impeller heights before making a gasket, that is if I have to make one.
Good to see someone has an analytical approach to a problem rather than jumping in head first.....
Select to expand quotecisco said..
If one thickness of chart paper is not enough, add another.
How do you find out it is too thin? If the plate is jammed against the rotor you might destroy it. However I cannot imagine a designer would make clearances that critical.
I think I will go with 0.4mm which seems to be the minimum on the market.
Select to expand quoteYara said..cisco said..
If one thickness of chart paper is not enough, add another.
How do you find out it is too thin? If the plate is jammed against the rotor you might destroy it. However I cannot imagine a designer would make clearances that critical.
I think I will go with 0.4mm which seems to be the minimum on the market.
Put the faces together dry, metal to metal, spin rotor by hand, you will know if binds.
For a little low-pressure gasket like that, it's almost certainly to be pretty thin, about .5 mm. But as said, use two thicknesses if you need to.
I got sick of the ridiculous Yanmar prices and measured the remains of the previous OEM gasket with the vernier then bought a minimum-quantity roll of paper from a bearing shop. For less than the cost of one OEM gasket I got enough paper to cover the next 1,000 engine services. Tapped them out with a little ball-pein hammer and now I have the next 5 years sorted.
Last gasket i made for a jabsco raw water pump i used a manila folder to cut out the gasket, coated it with oil and it's still ok 5 years on.
So the genuine Volvo-Penta part 833994 is only $6, and easily available, no need to make one unless in emergency. And the thickness? 0.15mm. Pretty darn thin, so not easy to make, and gasket paper this thin also not that easy to buy, and will cost more than the genuine article.
I have a great little laser cutter/ engraver that I mostly use for cutting small gaskets. I would probably do more with it but I need more practice with the CAD software. I sometimes use it for cutting fiberglass cloth for intricate parts as it seems to melt the cut edge and stop the piece coming apart
Select to expand quotecisco said..
Chart paper, hole punch, scissors and grease.
Can this thread move on??
Just for you Cisco, I measured the thickness of one of my paper charts, and yes, it was 0.15mm, just like the genuine gasket. However I am not going to attack my charts with a scissors unless desperate! :-)
Good one Yara. 
In the Navy out of date charts are passed on to the engineering department for recycling as gasket material for precision fit machinery.
In our application one could probably make 50 raw water pump gaskets from a chart so a if the chart is still in use on the chart table I really do not think a three inch square taken out of one corner of your chart in a time of need for gasket material is going to compromise navigation capabilities of the vessel to any great extent. 
What would we all be doing if we did not have such important matters as this to discuss??????????????
I have spare 50 charts, iam in qld. Manila folder plus touch of non hardening liquid gasket.
