Hello All:

     This question surfaced during our last flying session.  My two mates have decided to replace their metal tanks with plastic tanks.  Their reasons were varied and they were determined to make the change.

     What are your thoughts re making this change?

      Stay well,

      Frank

Frank,
The main advantage of the plastic clunk tank is weight savings. Generally, the plastic tank is half the weight of a tin tank. Also they are cheap, available and you can change them out quickly.  The disadvantage is the capacity sizes are pretty big jumps and the dimensions are a little wider than we normally use for say a FOX 35/OS 40 FP and are 1/4" deeper. So you need to have room to get the tank centered. Yes, you can adjust the uniflow if you use a fixed uniflow tube but most successful setups tie the uniflow to the fuel pickup clunk so it follows the fuel in the tank and keep the run smooth. So if there is room in the fuse it's good, if you need a specific dimension or capacity not so good.

Best,  DennisT

Seen referance to STAINLESS for a tank . No worries with Phosphoric based soldering acid .

How about CARBON tanks ? 

CLUNKS , V popular here . Metal . Some sealed . The odd one a screw top from a can incorporated .

Its said you can derange them , Storing NOSE DOWN . The clunk can fall forward and kink the tube .
PERMANENTLY .
So the ideas to do otherwise , hang from leadouts or nose or store flat . But DONT hold the Nose Down & jump up & down . Ever .

Hello I will use a plastic tank whenever I can find one with the right shape and the size I need otherwise that dreaded soldering iron comes out. For team race you have little option but to run metal and normally need to build yourself.  If you are very keen fiber glass and even  wooden tanks can be built but unless you run a diesel they will soften and break down in time.

Regards Gerald

The problem I have had with metal tanks is corrosion and other debris inside.  I never had this problem with the GRW tanks from years ago but whoever is making the metal tanks now must be using corrosive flux.  I was getting repeated filter clogs.  When I took the backplates off, one tank was completely rusted inside.  The other tank was partially rusted and there was other debris inside.  And, the uniflow line was not soldered to the fuel feed line.

With plastic tanks, I have had the neck split and the rubber stopper leak.  However, never a problem with debris or corrosion.

Take your pick.  Both work and both have problems of one kind or another.