23 replies to this topic

[SJ Lambert]

We're looking for a good paint type to use in conjunction with fuel tank sealant

Edited by SJ Lambert, 03 March 2014 - 22:27.

[Lee Nicolle]

James, production fuel tanks are made from turncoat material. Ofcourse they are pressed and roll welded though if formed properly the old trick of blind rivets and araldite should be fine. Personally I would make it from alloy then you can weld most of it and rivet/araldite the filler neck so as to put the foam in.
Elfin may have used steel originally but the alloy is more practical. And alloy welding then was an art form, now any competent welder can buy the equipment and use it. Though I would get an experienced fabricator to weld it together
The old steel tanks I have seen [Elfin Clubbie] were soldered. Not good in an accident as it will split.

[Catalina Park]

Lee, he isn't building a normal fuel tank. He is building one that you sit in and bolt the suspension to. It is an Elfin Mono. The car is the fuel tank.

[SJ Lambert]

Yep, there's a number of similarities, construction wise, between it and the 1965 Matra Sport (MS1) F3 Monocoque. I've recently been handed an article detailing the restoration of the prototype Matra Mono that was steel skeleton & steel panelling - it had been sealed with a sloshing compound and had rusted. It was reported to have aged poorly in that regard & I'm not sure whether the insides of the steel tub were painted or not.

Our car has stood the test of time pretty well vis-a-vis the "included" steel sections of tankage that were painted. So we'd feel comfortable coating them with paint again if we can hit upon a paint type that will seal/bond well with the sealant & not adversely react to sealant or avgas.

Edited by SJ Lambert, 10 January 2014 - 11:54.

[Catalina Park]

I would imagine some sort of epoxy paint but I'm no expert. There would have to be something used in aircraft somewhere.

You could always post some images so that we can see how an Elfin Mono was put together in the hope that it might attract some attention to your plight. (pretty please?)

[SJ Lambert]

How's this?

http://www.lotuselan...day-t30312.html

[Catalina Park]

Very good! The steel frame is nothing like what I imagined! 

[Greg Locock]

I'd talk to the aircraft restoration people if you can find any, or perhaps contact raychem and get some advice. I'm surprised 3M were useless as in my experience they were fun to work with and knowledgeable. Sorry, my contacts even if I could find them are 20 years out of date.

[mariner]

A very nice monocoque! - it is Matra - like. They were seen as a whole level above the UK fold and rivet guys when the first Matra F3 cars came out so it speaks well of Elfin's level of ambition.

 

May I suggest that age old standby for all plane builders/restorers -  Aircraft spruce and Speciality.

 

http://www.aircraftspruce.com/

 

They have a huge variety of stuff and very good technical service plus they ship overseas.

 

Long before the Internet I loved geting their catalogue and browsed it for hours even though I had no inention of buying or building a plane.

[Lee Nicolle]

Besides that Garrie had all the heavy duty folders there from the places body building days.

[JAW]

You could find out what was used to seal the RAAF's F-111 tanks, effective, but toxic to absorb, personally - apparently.

 

Or check with some war-bird restoration guys, & find out what they do to replace to old, original self-sealing tank bladders.

Edited by JAW, 13 January 2014 - 23:28.

[Catalina Park]

Did the F111 have painted steel riveted to alloy sheet and soaked in avgas?

[JAW]

Dunno the sophistications of the technicalities, F-111 tank sealing exactitude-wise,

avgas, avtur, rivets, composite-bonds, or what-have-you..

 

But I do know it was a problem-solving drama that has ongoing ramifications, even

after the machine has been retired..

 

That's why I suggested "...could find out..." - if it was of sufficient interest..

[Catalina Park]

He has the sealer. He just wants the paint for the steel.

[JAW]

But is it compatible?

 

Do you know?

 

I ask, since having frustrating issues with commercial sealers for motorcycle fuel tanks

( failing, peeling & clogging fuel systems) I reverted to a true impervious metal-to-metal seal..

Edited by JAW, 14 January 2014 - 06:54.

[SJ Lambert]

A sit down with the technical data sheet & some research on the substrates with good peel strength has allowed me to home in on one.

Edited by SJ Lambert, 04 March 2014 - 08:50.

[Catalina Park]

Good work, I was wondering how you were getting on.
I thought it would be something epoxy.

It might be worth hitting up any aircraft repair place to see if they have a litre or two left over.

[SJ Lambert]

1200 odd rivets later! - felt like it went together well!

Edited by SJ Lambert, 04 May 2014 - 00:18.

[bigleagueslider]

After all of that work, why not go a bit further and remove and strip the steel fuel tank panels. You can then epoxy coat and re-install them with a modern sealant material that will last decades.  The sealant compounds used back when this chassis was originally built would not likely still be in good condition, and simply covering it with a fresh coat of paint will not help.  Consider the potential problems resulting from pieces of the old sealant getting into the fuel system of your lovingly restored car.

[SJ Lambert]

We pretty much have gone the whole hog - skeleton back to bare metal and aluminium sleeve/outer panels/seat all cleaned up pretty well - sealant sticks to the paint better than it does to bare aluminium, but to both more than well enough!!

There was an awful lot of slosh sealant along the vertical panel/tank space in this second shot. It's been completely removed though, so we should get a good seal second time around.

I may put up a few more restoration shots on the Elfin Monocoque thread when I get the chance - http://forums.autosp...-100-monocoque/

Edited by SJ Lambert, 04 May 2014 - 08:10.

[bigleagueslider]

Sorry, but apparently I misunderstood what materials the chassis is constructed of. To be clear, these are aluminum panels riveted to a welded steel tube frame, right? If so, you'll definitely want to make sure every faying surface between the aluminum and steel parts is thoroughly coated and sealed from moisture intrusion. The surfaces of all parts should be thoroughly cleaned and given a coat of epoxy primer. When installing the new rivets, the rivets should be "wet installed" with the same primer. After installing each panel, all of the joints and rivet heads should be sealed using something like a brushable polysulfide sealant compound. This will be good for 20 years+, even when exposed to gasoline.

 

Good luck with the project.

[SJ Lambert]

We troweled the sealant on - & we're happy with the results. No photos of putting it together as we were on a schedule to get the 1500 rivets in before the music stopped!


http://forums.autosp...-5#entry6763022

[SJ Lambert]

Sloshed for good measure

[SJ Lambert]

https://www.youtube....h?v=gkMzu_yH8B4

 

We'll see if we can get over to Adelaide in a couple of weeks for the Historic Mallala meeting.

 

Wheel alignment scheduled for tomorrow........