gasoline+plastic - Subaru Enthusiasts Car Club of the Sierras

van · 2006-08-01, 08:07 PM

anyone know of a epoxy for plastic that won't get destroyed/disolved by gas?
I managed to break off a tab on my fuel pump assembly, the one that holds the float in place, fuel level sender I think. Will hot glue disolve? Any idea of what to use?

cody · 2006-08-01, 09:59 PM

Looks like epoxy is the way to go. I just did some quick googling.

http://www.airfieldmodels.com/inform.../adhesives.htm

Quote:

Fuel-proof

Fuel should not be able to get inside the airframe and fuel-proofness is not much of a consideration for general construction. Fuel tanks can and do split open from improper assembly, defective molding or design or a crash. The fuel compartment should definitely be coated with something fuel proof such as epoxy or polyurethane (paint). Joints around the firewall should also be glued with a fuel-proof glue.

http://www.rcrcc.com/adhesive_reference_chart.htm

Quote:

Epoxy -- This is a two part glue which is sold with various cure times and formulations. The two parts must be mixed to cause a cure. As a rule, generally faster curing epoxies tend to become brittle with time. Slow curing epoxy, in contrast, will tend to remain fairly flexible. Use this glue in all high stress areas such as attaching the firewall, landing gear blocks and tail feathers. Commercially available examples include the Hobbypoxy lineup as well as everybody else's house brands. It can be easily cleaned up with alcohol before it cures and is often thinned with alcohol and painted into engine bays and fuel compartments to help fuel-proof the plane. Smart people do this and recommend to all other modellers that they should also do this. Stupid people don't, and eventually their engine flies off with the firewall, leaving the plane behind. I was stupid once. God I hate fuel creep!

van · 2006-08-02, 05:29 AM

Awesome. Thanks for the research Cody.

Dean · 2006-08-02, 06:32 AM

RC planes use NitroMethane, so that data may not be accurate for gas. And being "fuel proof" to spray/leaks is different than geing submerged.

I'd see if the part is available and replace it rather than try and fix a part that gets submerged in a caustic liquid.

Almost every glue fails over time if exposed to something nasty. A Zip tie, or some sort of wire or clamp might be a better choice if you have to do something makeshift.

Dean · 2006-08-02, 06:39 AM

One more thought, if it is ABS, or PVC, one of those cements should work because they actually chemically melt/bond with the part and become part of the piece as opposed to sitting on the surface like an epoxy, or CA. (Super Glue)

van · 2006-08-02, 09:37 PM

I've got zipties holding the pump itself to the assembly, but they're too big for the "float". I think I will go with some thin copper wire and see if that doesn't block the movement of the arm. It's too damn hot to go pull another assembly out of the junkyard and I would probably fuck up another one trying to get it out off the tank anyway.
Thanks again for the input guys

rubberbiscuitt · 2006-08-04, 11:21 AM

will the copper be coated? even though i don't have a better solution, i just think that the copper will corrode faily quick.

2006-08-01, 08:07 PM	#1
van SECCS Brewmeister Join Date: Oct 2005 Location: on the edge of a marsh Posts: 1,451	gasoline+plastic anyone know of a epoxy for plastic that won't get destroyed/disolved by gas? I managed to break off a tab on my fuel pump assembly, the one that holds the float in place, fuel level sender I think. Will hot glue disolve? Any idea of what to use?

2006-08-02, 06:32 AM	#4
Dean Señor Cheap Bastarde Real Name: Dean Join Date: May 2003 Location: $99 Tire Store Posts: 9,294 Car: $.04 STI Class: Fast,Cheap & Reliable=STI Deal, did somebody say Deal? Oh, Dean, yeah that's me.	RC planes use NitroMethane, so that data may not be accurate for gas. And being "fuel proof" to spray/leaks is different than geing submerged. I'd see if the part is available and replace it rather than try and fix a part that gets submerged in a caustic liquid. Almost every glue fails over time if exposed to something nasty. A Zip tie, or some sort of wire or clamp might be a better choice if you have to do something makeshift. __________________ I am a Commodore PET --- Now get off my lawn you kids... Last edited by Dean; 2006-08-02 at 06:34 AM.

2006-08-02, 06:39 AM	#5
Dean Señor Cheap Bastarde Real Name: Dean Join Date: May 2003 Location: $99 Tire Store Posts: 9,294 Car: $.04 STI Class: Fast,Cheap & Reliable=STI Deal, did somebody say Deal? Oh, Dean, yeah that's me.	One more thought, if it is ABS, or PVC, one of those cements should work because they actually chemically melt/bond with the part and become part of the piece as opposed to sitting on the surface like an epoxy, or CA. (Super Glue) __________________ I am a Commodore PET --- Now get off my lawn you kids...

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2006-08-02, 05:29 AM	#3
van SECCS Brewmeister Join Date: Oct 2005 Location: on the edge of a marsh Posts: 1,451	Awesome. Thanks for the research Cody.

2006-08-02, 09:37 PM	#6
van SECCS Brewmeister Join Date: Oct 2005 Location: on the edge of a marsh Posts: 1,451	I've got zipties holding the pump itself to the assembly, but they're too big for the "float". I think I will go with some thin copper wire and see if that doesn't block the movement of the arm. It's too damn hot to go pull another assembly out of the junkyard and I would probably fuck up another one trying to get it out off the tank anyway. Thanks again for the input guys

2006-08-04, 11:21 AM	#7
rubberbiscuitt EJ22 Join Date: Mar 2006 Location: south lake tahoe Posts: 234 Car: L just push the brake pedal.	will the copper be coated? even though i don't have a better solution, i just think that the copper will corrode faily quick.