Sealing a leaking fibreglass tank. Not VMX

[DIRTPILOT72]

Not VMX. I was wondering if anyone knows how to seal a fibreglass tank. Its a Dingo type skid steer loader. Its leaking around the seam where the 2 halves are bonded together. The mounting bolts go through the seam to mount the tank. Its a diesel. I guess it would be similar to sealing a 2 stroke fibreglass tank? My main concern is the oily diesel on the inside of the tank.

[1983_Enduro_YAMI]

Any metal epoxy putty should do the job depending on how big the hole is   

[DIRTPILOT72]

Thats the problem, there is no hole, its seeping through the seam where the two halves of the tank are bonded together.

[1983_Enduro_YAMI]

Epoxy metal putty works well on a hairline crack as well or in that case you can also try fibreglass body filler. Just make sure you clean the surface before you apply the product 

[evo550]

Plenty of internal tank liners out there....Kreem is a brand that comes to mind.

https://www.youtube.com/watch?v=dT3vUX7vUGs

http://www.kreem.com/fueltankliner.html

[LWC82PE]

A bad hole could/should be fixed with fresh resin and some matting. If its tiny then i would use
https://redwhiteandblue.com.au/ which works excellent in fiberglass tanks.
Kreem is OK too but first preference/recommendation is R/W/B

if the seam is splitting, i would still try and dig it out along it with angle grinder/die grinder or whatever and get some resin there and sand back. It will need to be properly fixed if a long term solution is wanted, but i would still put a liner in it aswell. The old fibreglass resins do not like modern fuels. A lot of the Ducati shops use the R/W/B liner for this reason.

What ever you do, don't use f-ing POR15!

You will have to make sure you get inside of tank clean and oil free. Degreaser, hot soapy water with detergent, rinse with acetone etc.

[PeterC]

Recently sealed a fibreglass Bultaco petrol tank. Those are wirds of wisdom
Much soapy water, degreaser and finally when looks and smells clean acetone or similar
Die grinder on the seam to get out all the ratty fibreglass

[pokey]

Looks like the guys have covered it all. Cleaning is the issue as the oil gets in deep.
 The patch needs to be about three/four times what you think it needs, that oil travels a long way up the fibres . Multiple soaks of caustic and hot water and flushing and grinding, when it stops smelling like diesel your getting close to clean.

 I would consider adapting or making a different tank rather than playing with oily old glass and hoping  the repair held for awhile.. I mean its not a  hard to come by Vintage Euro bike tank  . Maybe drop the tank off at a sheetmetal fab shop for a quote on reproducing and factor in the cost of trying to fix the oily FG

[DIRTPILOT72]

Thanks for all the ideas. A tank liner product sounds like the best option.