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PVC gas tank question. Please help

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Old 02-15-2010, 09:30 AM
taddthewadd taddthewadd is offline
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Question PVC gas tank question. Please help

I have been looking for three hours through the forums here to figure out an alternative fuel tank. I really want to make one out of PVC but I can't seem to find a definite answer if the PVC will stand up to gasoline. Some posts say yes and some say no. I want to use PVC because it is easy to work with but I don't want to take a chance on ruining the engine or something else. Can anyone shine some light here? I know there are some of you who have had PVC tanks for a while. How are they holding up? Thanks in advance.
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Old 02-15-2010, 09:48 AM
atombikes atombikes is offline
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Default Re: PVC gas tank question. Please help

Interesting concept. Are you talking about using, for instance, a 3" diameter pvc pipe with end caps glued on? What would you use for the filler cap, and how would you incorporate that? Not sure if putting gasoline in pvc is "a really bad idea (tm)" but it may be illegal depending on where you live?
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Old 02-15-2010, 10:23 AM
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Default Re: PVC gas tank question. Please help

Tadd, definitely an interesting idea. I'm playing with ideas for alternate gas tanks as well, so I got on Google and here is a summary of the first three results.

1. One website (Chemical Resistance Chart - Jensen Inert Products) describes PVC's gasoline resistance as "good".

2. Another website shows where a guy did a 54-hour gasoline immersion test and decided the same thing (SpudTech Archive • View topic - PVC Pipe Gasoline Resistance Test).

3. Here is a Wiki question (Can PVC pipe be used to handle gasoline and will the regular glue used hold? - Yahoo! Answers), I don't have any idea what the qualifications of these people are, but they all seem to be in agreement.

I think the most definitive way to determine the gas resistance of a PVC tank would be to go for it - build it, keep an eye on it to ensure its safety, and then us how it went .
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Old 02-15-2010, 12:07 PM
taddthewadd taddthewadd is offline
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Default Re: PVC gas tank question. Please help

I am going to try it. Connonfish, thanks for the links. That gives me the confidence to do it. And as for atombikes question, I have seen on threads here people threading the pvc with a tap and using brass plumbing fittings for fuel outlet and vent tube. As for the cap to fill the tank you can use smaller pvc fittings. A dremmel tool will come in handy for this part.
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Old 02-15-2010, 12:26 PM
taddthewadd taddthewadd is offline
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Default Re: PVC gas tank question. Please help

I just re-read atombikes question about how to make the pvc tank and I realized I could do a better job of answering that so here goes...

Yes figure out what capacity you want and use the size of tubing acording to desired capacity. Probably 3-4 inch would be good.

Then you need to make three holes in the tube. One for vent, one for fuel line to carb. and a bigger one for the filler cap. The tubing is thick enough that you can use a tap to thread the holes. You would only need to tap and thread the vent line hole and fuel line hole. You can thread brass fittings in those two holes for the vent hose and fuel hose. I plan to use jb weld or something on the threads to help seal it since there wont' be a whole lot of threads due to the thickness of the pipe.

Next you need to make the filler cap. I would cut a hole with a dremmel tool in the main pipe and glue a smaller diameter pipe for a neck (maybe 1" pipe) then you can put a threaded fitting on that pipe and use a threaded PVC cap for the gas cap.

Finally gule on the two caps at either end of the main tube to seal off the tank.

As for the vent line there are a couple of ways to keep gas from leaking out of it. One is a check valve which is a little plastic piece like a one way valve that lets air in the tank but won't let the gas out. You can buy this at a lawn mower shop. Or some people put a fuel filter in the vent line and the gas is absorbed by the filter and goes back in the tank.

Hope this helps.
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Old 02-15-2010, 05:24 PM
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Default Re: PVC gas tank question. Please help

Be advised there are two types of PVC, if you are going to drill and tap I would advise avoiding the "foam core" type. Foam core PVC is constructed with a smooth inner and outer surface sanwiching a lighter density core. I learned about this building a spud gun last year.
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Old 02-15-2010, 05:28 PM
atombikes atombikes is offline
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Default Re: PVC gas tank question. Please help

Quote:
Originally Posted by K.i.p View Post
Be advised there are two types of PVC, if you are going to drill and tap I would advise avoiding the "foam core" type. Foam core PVC is constructed with a smooth inner and outer surface sanwiching a lighter density core. I learned about this building a spud gun last year.
Excellent point that may not have been thought of otherwise!
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Old 02-15-2010, 05:30 PM
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Default Re: PVC gas tank question. Please help

The volume of one gallon is 230.999952 cubic inches. Find the number of square inches of your desired diameter pipe (Pi x radius squared). Multiply this by the length of your tank to calculate total cubic inches. If you arive at 115 c.i. you have a 1/2 gallon capacity and so on. Good luck!

Last edited by K.i.p; 02-15-2010 at 05:38 PM.
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Old 02-15-2010, 06:13 PM
taddthewadd taddthewadd is offline
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Default Re: PVC gas tank question. Please help

I used to work in a hardware store and there were two types of PVC the "schedule 40" was thicker and could hold more pressure. This must be the one to use. Maybe the other PVC was the foam core you are talking about. Please correct me if I am wrong.
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Old 02-15-2010, 09:18 PM
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Default Re: PVC gas tank question. Please help

If the pipe is meant for pressure, it will say "nsf-pw" on the side (North America). "nsf-dwv" is low-pressure (drainage) applications. "cellular core" means it'll explode if a kitten jumps on it.





Ok, I'm exaggerating about that last one.
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