Lotus Elan Central

Hard to say at this stage if this is going to be a Minor or a Major Project!

If anyone wants to follow progress, I've got an album on facebook showing the project.

Please ask if any particular pictures would be of help or interest.

Petrol Tank Repair

Gordon

Well, the tank's off (see facebook link).

It was leaking fuel when filled over 3/4 which is why it's off (I suspected filler neck) - However - now it's off it's not obvious where it's been leaking from!

Not a problem as such, I'll pressure test it - My question is, what would one consider a reasonable pressure to take the tank up to?

Any suggestions taken onboard!

Gordon

These are not pressure vessels so if testing for leaks.
If it was leaking when above 3/4 full then here's a sugestion
Fill it with water and add a clear pipe say 6ft long higher than the tank if you fill it to a level in the pipe and the level stays the same you have no leak if it drops then you have a leak and you should be able to see where it is comming out.
This way you are only putting a very small head on the tank around 2.5psi.

Bob

Cover the outside in spray chalk or possibly talcum powder, blank off the orifices and roll or stand the tank at different angles. This will show the leak and save you having to put water in the tank. You may have enough fuel in the tank already.

TTFN

If anyone wants to follow progress, I've got an album on facebook showing the project.

and the point of this forum is

Yes we are interested Gordon but were not all on facebook

The album should be public - you should be able to see it without "joining" facebook;
I'm using it as a publishing medium, certainly not endorsing membership!!

Steve A wrote:

If anyone wants to follow progress, I've got an album on facebook showing the project.

and the point of this forum is

Yes we are interested Gordon but were not all on facebook

I'm using it as a publishing medium

Oh yeah tried it earlier and it didn't work , nice pictures

Thanks Bob - it hadn't occured to me that the tank is not designed to stand much pressure at all!

And Specky - Excellent idea - I must admit dread at the idea of putting water in the tank - had a friend mess up his injectors on a Kia after an incident with water!!

Just need to find something suitable to block the pipe holes up now! - there's still half a gallon in it, so plan should work!

Gordon

I can't take the credit, it's an old trick that was taught to me in the 80's.

It's a perfect way to find a leaks when the suspect area is just to dam dangerous to be in.

Just remeber you're not putting on talc after getting out the bath, a thin dusting is what you require this will show the leak as a stain.

Start on the suspect area first.

TTFN

OK, Leak located...

Now I need something that can glue (and preferably build) HDPE plastic...

I've heard of "Pro-Poly" and "Plastex 3000" - anyone any experience with either of these - or any other suggestions?

I find myself entertaining the idea of conventional hot-melt glue - especially since it's not a pressure tank (thanks Bob) - but that may be a no-no?

Gordon

QBond is what has been suggested and used by Steve Willams before according to threads on here.

JonT wrote:QBond is what has been suggested and used by Steve Willams before according to threads on here.

I read through those threads... there seems to be some doubt as to the lifetime of the repair - 2 years isn't really enough.

My understading of Q-Bond is that it's excellent for hard plastics - HDPE (like polypropylene) is notoriously difficult to glue - usually being done using melt - welding...

PRC 1422 A1/2

Just slap it on. Stinks like s**t, I've used tons of the stuff over the decades.

http://cgi.ebay.co.uk/PR1422B-SEALANT-a ... 1e60e635cf

If you chose this option, PM for my No and I'll tell you the Do's and don'ts with this product


TTFN

Looks like interesting stuff - read through the data sheet, and cant find any reference to adhesion to HDPE?

It does make reference to priming surfaces though, - again unsure what HDPE could be primed with that would provide a key?

Have you used this on soft plastics personally?

Thanks for the pointer,
Gordon

Specky wrote:PRC 1422 A1/2

Just slap it on. Stinks like s**t, I've used tons of the stuff over the decades.

http://cgi.ebay.co.uk/PR1422B-SEALANT-a ... 1e60e635cf

If you chose this option, PM for my No and I'll tell you the Do's and don'ts with this product


TTFN

I've used it on all manner of plastics, metals and paints.

just rough up the area with a bit of coarse sand paper.

I've used the product as an external weather seal, it also prevents dissimilar metal corrosion, fuel tanks.

Don't forget, you can access both sides as it's on the neck, a double seal as such.

Hope that helps.

TTFN

Opinions on this product anyone?

3M-Scotch-Weld-4693H-Polyethylene-Polypropylene
3M-Scotch-Weld-4693-Polyethylene-Polypropylene

I think we all generally agree that we like 3M...

Don't forget there's more than one way to skin a cat, you could cut the damaged neck out and then bolt in a metal neck.

It'll be a bugger to get the backing plates in though, you'll also require sealed anchor nuts on the backing plate.

you'll still need a couple of seals or something similar to the sealant mentioned earlier

Remember to use hand tools or air powered tools,

TTFN

Gordon wrote:Opinions on this product anyone?

3M-Scotch-Weld-4693H-Polyethylene-Polypropylene
3M-Scotch-Weld-4693-Polyethylene-Polypropylene

I think we all generally agree that we like 3M...

We use numerous variations of Scotch weld and scotch clad, but I've never used that one, is it fuel resistant?

I can check it out at work tomorrow if you like.

TTFN

Specky wrote:

Gordon wrote:Opinions on this product anyone?

3M-Scotch-Weld-4693H-Polyethylene-Polypropylene
3M-Scotch-Weld-4693-Polyethylene-Polypropylene

I think we all generally agree that we like 3M...

We use numerous variations of Scotch weld and scotch clad, but I've never used that one, is it fuel resistant?

I can check it out at work tomorrow if you like.

TTFN

Please -

the PDF claims oil resistance...
I'm keen as it specifically claims high bond to this class of plastics... and of course it's being used as much as a cork as anything?!
4693H I would think - the other (low viscosity) one seems to be liquid, for spraying use?

Just had a quick look on tinters, it's a crackin little contact adhesive.

Think clear evostick with attitude. It's not a glue I would use to seal a petrol tank though.

The main reason for saying this is, it's a contact adhesive.

TTFN