DragBikeMike wrote on 06/30/22 at 23:07:39:Awhile back my intake elbow fell apart. It was a 2” street elbow made from ABS plastic. Best as I could figure, the aromatics in the fuel attacked the plastic and it crumbled apart. I replaced it with a 2” PVC street elbow. I didn’t like the look of the white PVC, so I painted the replacement elbow with black paint. The PVC elbow is holding up well. It has yellowed on the interior, but there is no evidence of deterioration. It’s also clean as a whistle. Zero dirt. The K&N filter is takin care of business.
If you ever need to replace it, have a look at CPVC. That is what you use for hot water.
I don't know if JB weld is like bondo, except that it is an epoxy. If you're looking at a place that just won't straighten enough to only need a shallow application of bondo and you Have to apply a deep stack of bondo, you can't do it in one pass. It's gonna crack. You hafta put it on in layers. Naturally, clean and dry surface, then, pressing the bondo onto the surface, " Wetting "it, add enough to be able to scratch it with something like 40 grit,to give it Teeth so the next application will stick, rinse and repeat.
If you could find something that would take the heat, be non metallic and flexible to use like rebar,that would be good.
When I was working on a cab over truck that had been sand blasted using heavy media, I used six gallons of mud. Passenger side had been punched just above the headlight. The floor was buckled up. It was aluminum, I had nobody to hold a backup hammer while I smacked it from the other side. I don't remember how I got ahold of it to pull it with the come along, but I got it hooked up. It just slid the fork lift, so I grabbed a few welding rods,got the flux off of them and started building that area up until it was pretty deep, drilled a coupla holes and put a rod in the mix. Built it up more, added another rod, I think I used three, not sure anymore..
But the moral of the story is, my body man buddy told me I was going to see it crack and fall out. I saw that truck, up close, about five years later, when they retired it.
No cracks. And it was a West Texas oilfield truck, so it got rattled hard goin down those roads.
Ahh! And another thing about epoxies. Yeah, the instructions tell you how to mix it. But if I want it to not be brittle I use less hardener.
Trying to get a large area covered in one pass is difficult, especially if it is a hot day.
YaKnow, you can almost stop epoxy from curing by putting it in the freezer.
If you want to try an experiment you could mix a batch and make three lumps.
Smear half of one thin,leave some scooped together to make it thick
In the freezer it goes
Another of them, all from the same mixture
Just leave it where you are working
The third, in the sun and hopefully some breeze.
I got a blister from some five minute epoxy I mixed up and had a fan blowing on it.
If you mix it up light on the hardener you can put a drop light near it.
My boss was pretty upset when I mixed up enough to cover the whole roof of a big four door car and it looked like it would never dry. Parked it in the sun, and about an hour later I had a roof with a uniform application of mud. Quick and easy to finish because it wasn't a patchwork of areas of varying hardness.
never dry,,everyone does that once in a while..