injector bosses

[Seth]

On Fri, 29 Aug 1997, Tom Cloud wrote:

> 
> >A *true* epoxy will cure faster and harder when heat is applied
> >(remember, it's a plastic, so it has an upper limit where it's
> >damaged or destroyed .... I forget, but I think it's near 300 F).
> >Also, it will *resist* solvents and hot water (see below about fast-
> >curing epoxies).
> >
> >
> > ** be aware that five-minute -- quick curing -- epoxies are
> >   not *true* epoxies (don't really know the chemical difference)
> >   and won't get as hard, are damaged by heat, are softened by
> >   hot water and by gasoline -- i.e. don't use them !
> 
> one last thought about epoxy -- that's probably what's
> in the connectors on the engine -- ex. sensors, etc -- for
> the seal and to hold the connector pins in place .... could
> even be a component in the injectors ??
> 
> Also, epoxy will (should ?? ) stand as much heat as the
> wiring on your engine (of course, the injectors are in more
> direct contact with the engine heat).
> 
> Tom Cloud
> 
> They say the mind is the first thing to go ... and I can't remember the second
> 


I deal with room temp cure epoxies pretty much all day ( lots of carbon 
fiber lamination and bonding)  that stuff is the nasty aliphatic amine 
hardener.  It is a "real" epoxy. But even 5 minute epoxy  has aliphatic 
amine as the "hardener".  In either case, aliphatic amine expoxies don't 
like heat much.  Viton, that fluoropolymer engineered for heat and oil 
still dies eventually, ever try to remove old CIS O-rings?  

I might suggest a urethane adhesive, they often have higher sevice temps, 
gap fill better and adhere better than epoxies.  They also can emit 
di-isocyanates, so you want to be a bit careful.  But the stuff works 
where epoxy won't.

Personally, I weld if I can, but I am a welder at heart, and I like the 
look of a nice bead.


Seth