no not at the threads they crack around the fitting in the cap, only had that happen when I left gas in the tank, I have now started using the PSP caps

Having the inside and outside nipples integrated as all in one with the aluminum cap eliminates the cracking.

Scott

They radiate out from the center of the cap.

Originally Posted by ericb

They radiate out from the center of the cap.

Yep, over time the gasoline or whatever that stuff is LOL will break down the plastic most caps are made of. That's why I like the stopper I machine...the fuel never even touches the cap...and if you don't want to use a cap, heat shrink would also work fine.

Originally Posted by ericb

They radiate out from the center of the cap.

That's because the hole made to accept the fitting is too small.

When I first started making my own tanks using Fiji water bottles, I would try to get a snug a fit around the fitting in the center of the cap and discovered that this placed pressure on the cap thus causing the cracks to radiate. I now ensure the fitting slides in easily and haven't had the issue since. An o ring around the fitting prevents leaking.

DaleD

The first soda pop tank I assembled and installed in 2006 was to keep the weight of everything in my airplane as light as possible, not because of a spitting Dubro tank. Anyway the same tank is still installed and serviceable today.

Bob

Originally Posted by littlecrankshaft

Yep, over time the gasoline or whatever that stuff is LOL will break down the plastic most caps are made of. That's why I like the stopper I machine...the fuel never even touches the cap...and if you don't want to use a cap, heat shrink would also work fine.

crankshaft, is your stopper the one available on ebay?

Originally Posted by Truckracer

crankshaft, is your stopper the one available on ebay?

It is. I bought one myself. Pretty nice.

Originally Posted by JoeAirPort

It is. I bought one myself. Pretty nice.

Thanks Joe.

I forgot to mention in the listing that the stopper has an oversize ID on the nipple so it can feed the larger engines without worry.

I used DuBro tanks since the 70s. When I got out of nitro and started flying gas and had to re-plumb the tanks once a year with Tygon tubing the brown gas stoppers were always a pain to get out and replace. Set up my first Fiji water bottle about two years ago using all PSP fittings and never looked back. I get all the PSP fittings from Chief Aircraft and the bottles from my local Raleys. Way lighter, easier to maintain, you can see inside, they don't leak. Try one, you'll like it.

I never looked back after going PSP either. Great quality that works great. I also like the slim 90 degree fuel fittings that Taildragger RC sells.

Thanks for the info...Been out of the hobby for a few years....

Originally Posted by DaleD

That's because the hole made to accept the fitting is too small.

When I first started making my own tanks using Fiji water bottles, I would try to get a snug a fit around the fitting in the center of the cap and discovered that this placed pressure on the cap thus causing the cracks to radiate. I now ensure the fitting slides in easily and haven't had the issue since. An o ring around the fitting prevents leaking.

DaleD

Not always. That was the problem initially, but after enlarging the hole, I still had some crack over time.

Here is my favorite.

This is a bottle used for mailing animal manure samples.

The best thing is that you can get these free from the national soil fertility center. The bottle is very sturdy, sturdier than any of the standard fuel tanks I have seen and yet light enough for this purpose. The bottle cap is large enough to make tubing installation a very easy task. Given the stuff which is normally put into these bottles the cap can be tightened very tight and is guaranteed not to leak. As an extra measure of safety I use a spring in the cap which prevents it from opening.

I highly recommend using the fuel filter used in chain saws such as Husqvarna as the clunk inside the tank. This thing will suck the last drop of fuel from the tank.

--kaboomski;

Wow methane and gasoline, what a combination!! How many extra HP does it produce and did you have to slightly retard the ignition?












We have 16 inches of snow fall so far. I think Cabin Fever is setting in!