Pressure Testing a New Tank

Status
Not open for further replies.
Tornado

Tornado

VIP MEMBER
Joined
Dec 5, 2017
Messages
4,520
Country flag
Moving forward with plans to get a CS re-production raw steel tank painted up. Have tried a homemade setup to test for any leaks....learned from a YouTube video on a home-build aircraft fuel tank maker showing to just attach a nitrile glove around the filler opening using elastic bands. Then to blow into an outlet nozzle until the glove inflates and leave it to sit overnight. Any significant lose in glove inflation not accounted by temp changes indicates a leak and to then proceed with soapy water spraying on seams/fixtures etc.
Well, doing this gave glove deflation in only a matter of 15-25 minutes. Tried double wrapping the glove with elastics but no improvement. Went hunting with soapy water but could not see any obvious leaks.
Any other tips or does it need to go a a radiator type shop for more professional checking?
 
Of course not! I only use the very best Chinizium nitrile gloves.....same place that makes my condoms I believe ;-)
 
The way I test is to get a plumbers test plug that fits the gas cap opening (1 1/4" I think). Build an air valve from an old petcock and a valve stem or similar. Use a hand pump to put in 4 or 5 lbs, dunk under water and look for bubbles or just a bubble as it doesn't take much of a leak to lift your paint job. DO NOT USE A COMPRESSOR! Much more pressure will blow the tank up like a balloon and it will be ruined. If you take it to a radiator guy, make sure he has done motorcycle tanks before as radiators are tested at higher pressure with no damage.
 
Good advice but would do it yourself to save drama.
Remember Alan Hodge (sp) did that with the exact same tank, he took a Norton tank in and got the radiator shops rendition of a puffer fish back.

I believe the tank was not only ruined but leaked anyway so was scrapped.
 
Tornado said:
...
Any other tips or does it need to go a a radiator type shop for more professional checking?
Click to expand...

i found that once i filled them with gasoline the leaks became visible... just fill it since its not a sealed under pressure system anyway.

as an asside i think that the Emgo reproduction may be better the the CS one? i have seen dissatisfied discussion regarding the CS one. but no personal experience
 
brokeneagle said:
The way I test is to get a plumbers test plug that fits the gas cap opening (1 1/4" I think). Build an air valve from an old petcock and a valve stem or similar. Use a hand pump to put in 4 or 5 lbs, dunk under water and look for bubbles or just a bubble as it doesn't take much of a leak to lift your paint job. DO NOT USE A COMPRESSOR! Much more pressure will blow the tank up like a balloon and it will be ruined. If you take it to a radiator guy, make sure he has done motorcycle tanks before as radiators are tested at higher pressure with no damage.
Click to expand...
Did the same with a bath plug in the gas tank opening. Used a ratchet strap to hold it in. Then cut down a tyre valve to fit in the petcock and pumped it up with a bike pump until I got the gauge to just move (4-5 psi) then put it in the bath. All good.
 
Put a piece of tape over the breather hole on the metal disc of the filler cap. Put a cap on and peacocks in and close all of them. Fill a bathtub with warm water. Submerge and hold down with one hand on top of the cap to prevent pressure escaping. Look for bubbles. Dry tank off when you are done!
 
gortnipper said:
Put a piece of tape over the breather hole on the metal disc of the filler cap. Put a cap on and peacocks in and close all of them. Fill a bathtub with warm water. Submerge and hold down with one hand on top of the cap to prevent pressure escaping. Look for bubbles. Dry tank off when you are done!
Click to expand...

Man, I think those peacocks would be mighty PO'd being inside that tank underwater! :)




Don't you just love auto-spell? ;)
 
Tornado said:
USA made.
Click to expand...

I think your tank started off in India one way or another ?

I can't knock the made in India stuff, I picked up an Interstate tank (6+ kg bare weight) years ago and it still looks good in bare metal, it will be on the plane to New Zealand with me tomorrow for delivery to its new keeper.... 3000kms + riding around India was fine also, maybe even a trip back this year.

What I would like is a steel EMGO Fastback fuel tank.
 
Last edited:
I plug the filler with an expanding rubber plug, fit a pressure gauge to one petcock opening and hook an air adjusting valve with gauge off my spraygun to the other petcock hole. Hook the line from my compressor to the valve and open it to 4 or 5 psi. Shut it off and look for a drop in pressure on the other gauge. Saves leaving a ring in the bath tub.
 
Why all of the sub tactics when you can just pick up a bottle of Snoop or use water/dish soap & set it up on the bench? It'll bubble up at any leak with the 3-4# pressure pinpointing the leak/s leaving the tank dry and easy to mark. Just saying......Just squirt a bit along the seams & welds, or any suspect areas your heart desires because it bubbles for a considerable time on the leak. If there is one.
 
Time Warp said:
I think your tank started off in India one way or another ?

I can't knock the made in India stuff, I picked up an Interstate tank (6+ kg bare weight) years ago and it still looks good in bare metal, it will be on the plane to New Zealand with me tomorrow for delivery to its new keeper.... 3000kms + riding around India was fine also, maybe even a trip back this year.

What I would like is a steel EMGO Fastback fuel tank.
Click to expand...
Nope...Commando Specialties makes them in USA....see their announcement blurb on their site:
https://commandospecialties.wordpress.com/2012/05/24/need-a-new-norton-commando-roadster-gas-tank/
jbruney said:
Why all of the sub tactics when you can just pick up a bottle of Snoop or use water/dish soap & set it up on the bench? It'll bubble up at any leak with the 3-4# pressure pinpointing the leak/s leaving the tank dry and easy to mark. Just saying......Just squirt a bit along the seams & welds, or any suspect areas your heart desires because it bubbles for a considerable time on the leak. If there is one.
Click to expand...

I did that while I had the nitrite glove inflated over the filler, but could not see any bubble points, I do suspect leakage at one/both petcock as they are junk ones with badly worn seals. But again, didn't see bubbles with soapy water. Might be the Wife all natural dish soap just doesn't make good bubbles.
 
Status
Not open for further replies.
Back
Top