Sciencemadness Discussion Board

Epoxy for Fuel System

Gru - 8-8-2020 at 04:20

I have had a little mishap while replacing the fuel tank in a vehicle. There is a long white plastic manifold at the front of the tank (see video)
https://www.youtube.com/watch?v=c31T7WmjSjM
which is a part of the fuel evaporative emissions control (EVAP) system, best shown in the clip at 0:12.

The purpose of this manifold is to contain fuel fumes, and route them to the engine for burning when it is running. The manifold has cracked and I would like to repair this rather than go to the hassle of obtaining another one. There are a couple of reasons for this, mainly, 1) the part is not available commercially, and 2) the tank must be removed for this and it is a lot of work with no lift.

The only epoxy I have right now is Gorilla Epoxy https://www.gorillatough.com/product/gorilla-epoxy/
It claims "superior solvent resistance", but on the packet it also says "not recommened for polyethylene and polypropylene plastics"

Simply, can I use this (or can anybody recommend a product).

Gru - 10-8-2020 at 04:30

After far too long researching this, I have found the following conflicting piece of information
Quote:


Many objects are made with polypropylene precisely because it is resilient and resistant to most solvents and glues. Also, there are very few glues available specifically for gluing PP. However, solid PP objects not subject to undue flexing can be satisfactorily joined with a two-part epoxy glue or using hot-glue guns. Preparation is important and it is often helpful to roughen the surface with a file, emery paper or other abrasive material to provide better anchorage for the glue. Also it is recommended to clean with mineral spirits or similar alcohol prior to gluing to remove any oils or other contamination. Some experimentation may be required. There are also some industrial glues available for PP, but these can be difficult to find, especially in a retail store.



https://en.wikipedia.org/wiki/Polypropylene#Repairing


And according to this chart, gasoline resistance is no problem
https://www.engineeringtoolbox.com/chemical-resistance-epoxy...


Other weapons in my arsenal include Rectorseal EP-200 epoxy putty, superglue (doubtful), and a hot glue gun (perfect, but it's resistance to fuel is questionable)