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Clubroom => Tech Talk => Topic started by: John Orchard on January 28, 2019, 06:52:48 pm

Title: Fuel resistant glue for bonding rubber to metal?
Post by: John Orchard on January 28, 2019, 06:52:48 pm
I have to glue a rubber seal into my metal fuel tank cap, anyone have experience with a particular glue?
Title: Re: Fuel resistant glue for bonding rubber to metal?
Post by: pokey on January 28, 2019, 07:42:18 pm
You should have some three bond or the yamaha  sealant handy, That should do the trick.
Title: Re: Fuel resistant glue for bonding rubber to metal?
Post by: sleepy on January 28, 2019, 09:44:43 pm
I would try contact adhesive, it seems to last quite well around petrol. Three bond however if it is the silicon type does not work if any liquid petrol is around.
Title: Re: Fuel resistant glue for bonding rubber to metal?
Post by: dont on January 29, 2019, 08:18:30 am
There us a common boot makers glue I got a recommendation for that seems to be working on a carbie plastic intake. But on a metal tank exterior I've used tarzan grip and its been fine.
Title: Re: Fuel resistant glue for bonding rubber to metal?
Post by: pokey on January 29, 2019, 06:25:23 pm
Yes definitely NOT the basic Silicone Threebond but the high temp RTV version.
Contact cement uses a hydrocarbon as a solvent and it turns to a Gel when in contact so not the best idea. All the Bootmakers adhesives use hydrocarbons as solvents(bootmakes choice, PVC adhesive and the rubber contact adhesives) .

What you could try is a cyanoacrylate (superglue/locktite) as its good for metal surfaces and nitrile rubber and does not use hydrocarbons as a catalyst. clean the surfaces well. This adhesive as you know is not flexible so i would try the RTV threebond first.
Title: Re: Fuel resistant glue for bonding rubber to metal?
Post by: jimson on January 29, 2019, 07:43:56 pm
Can you cut an old tube up like a flat washer and force it over the neck of the lid so it acts like a seal between the 2, when its shut  ? jimson
Title: Re: Fuel resistant glue for bonding rubber to metal?
Post by: John Orchard on January 29, 2019, 10:02:34 pm
Can you cut an old tube up like a flat washer and force it over the neck of the lid so it acts like a seal between the 2, when its shut  ? jimson


Good idea, l'll look at that, thanks everyone :-)
Title: Re: Fuel resistant glue for bonding rubber to metal?
Post by: pokey on January 30, 2019, 01:04:18 am
I'm guessing this is for the dt?
Many moons ago I had issues with a Suzuki ts cap that would leak. Suzuki use the hinged clam spring loaded style and it took awhile to work out why an extra rubber washer was causing issues. It didn't leak but it ran like a pig.
Under that internal spring plate was a sponge baffle and a small gap needed as a breather. The extra thickness cleared the gap.
I'm guessing again that the DT cap also has a breather system it needs to vent to atmosphere.  Something to think about.
Title: Re: Fuel resistant glue for bonding rubber to metal?
Post by: dont on January 30, 2019, 07:48:11 am
Can you cut an old tube up like a flat washer and force it over the neck of the lid so it acts like a seal between the 2, when its shut  ? jimson
I've done similar to this but found the ordinary rubber disintegrated. I bought some petrol compatible sheets im various thickness from a place in melbourne and it worked well. Makes new seals for petrol taps too.
Title: Re: Fuel resistant glue for bonding rubber to metal?
Post by: John Orchard on January 30, 2019, 09:19:36 am
Yes it is on a DT tank with a flip-up cap :-)

 l realized that a fuel tank cap has to breath so l drilled a very small hole through the post that the sealing washer slides up & down,  tapped a thread in the top of the cap and fitted a 5mm screw with a a hole drilled through it also, on this screw (with the head cut off) l can fit breather hose, with an inline fluid check-valve. l sealed around the outside of centre-post so that fuel could not escape via the original breathing passage. This way l have control where fuel might come out.

The original sealing washer around the outer edge of the spring-loaded washer has long since vanished, which started the whole process. l will experiment with a full-coverage rubber seal, held on by the centre circlip, this should be easier than trying to seal just the outer edge of the spring-loaded washer.

Good work if you can decifer my explanation ;-) Thanks again for input, man l am so impressed by the knowledge that is shared on the website.
Title: Re: Fuel resistant glue for bonding rubber to metal?
Post by: jimson on January 30, 2019, 07:01:32 pm
(http://i30.photobucket.com/albums/c315/jimson13566/20190130_185613_zpsctq9a29x.jpg) (http://s30.photobucket.com/user/jimson13566/media/20190130_185613_zpsctq9a29x.jpg.html)
A while back I changed the cap on this tank
Title: Re: Fuel resistant glue for bonding rubber to metal?
Post by: jimson on January 30, 2019, 07:03:54 pm
(http://i30.photobucket.com/albums/c315/jimson13566/20190130_182722_zps0udgodpi.jpg) (http://s30.photobucket.com/user/jimson13566/media/20190130_182722_zps0udgodpi.jpg.html)
Title: Re: Fuel resistant glue for bonding rubber to metal?
Post by: jimson on January 30, 2019, 07:07:43 pm
(http://i30.photobucket.com/albums/c315/jimson13566/20190130_182745_zpsvtxmhkhw.jpg) (http://s30.photobucket.com/user/jimson13566/media/20190130_182745_zpsvtxmhkhw.jpg.html)
Title: Re: Fuel resistant glue for bonding rubber to metal?
Post by: jimson on January 30, 2019, 07:09:17 pm
(http://i30.photobucket.com/albums/c315/jimson13566/20190130_182757_zpsr7isdoc2.jpg) (http://s30.photobucket.com/user/jimson13566/media/20190130_182757_zpsr7isdoc2.jpg.html)
Title: Re: Fuel resistant glue for bonding rubber to metal?
Post by: jimson on January 30, 2019, 07:11:11 pm
(http://i30.photobucket.com/albums/c315/jimson13566/20190130_182841_zpsaklwydjf.jpg) (http://s30.photobucket.com/user/jimson13566/media/20190130_182841_zpsaklwydjf.jpg.html)
Title: Re: Fuel resistant glue for bonding rubber to metal?
Post by: jimson on January 30, 2019, 07:17:20 pm
From memory I bought the alloy pipe pretty much the right size, cut it to length  and put it in the lathe to make a channel so a O ring could fit, but it was to tight. If you look at one of the pics theres an O ring at the top of the pipe it seats really well in when the cap is pushed on & turned. jimson
Title: Re: Fuel resistant glue for bonding rubber to metal?
Post by: John Orchard on January 30, 2019, 08:30:44 pm
So the alloy tube is an interference fit, or soldered into the tank? and the cap locates onto the alloy tube?
Title: Re: Fuel resistant glue for bonding rubber to metal?
Post by: jimson on January 30, 2019, 09:31:41 pm
I've only used the alloy pipe on the lid. The opening on the fuel tank, is just from carefully removing the old locking cap. jimson