I have a crappy welder, therefore, I have crappy welds. I basically have to weld a bunch too much, then grind down flat, but it still leaves pits. Here is what I have so far...should I use bondo to fill in the pits before I clean and paint the engine bay? Before... And After...
After you have it cleaned up, you might think about coating it with POR-15 or Rust Bullet. If the pits are small, it should fill them in and protect the area for the future. These products are sandable and paintable too.
Didn't even think of POR-15...good idea. I think I will do a coat of bondo to fill in the deep pits, then POR-15 over it. I am assuming POR-15 will stick to bondo....
I would not try to put POR-15 over bondo. My thought: Prepare the surface for POR-15, then use POR-15, then use some high-solids primer/filler primer (within POR-15's recommended timeframe so you don't have to scuff it). At that point you shouldn't need much filler.
I guess I should pay a visit to POR-15's website and get specific instructions on how to do that. I did hit it some more with the sander and got more of the pits leveled out. I hate flux-core mig welding...Someday, when I grow up, I will get one that accepts gas...
So I take it your welder can't be upgraded to use gas. It's definitely a LOT nicer if you've used both.
Use a fiberglass based body filler. They're less likely to absord any standing water or acid that might settle there later.
My welder is a $99 Harbor Freight special. I got it before I got serious on this project. It is fine for heavy metal, like the shock tower 1/8" plate, but for sheet like this 22 gauge, it is not too good. It does not accept gas. I borrowed Rolandag2's welder and bottle and it welded MUCH nicer (for another project). I just don't have the funds right now to upgrade. Need to, though... I have sanded it down pretty good, I might be low enough that straight POR-15 will fill in the pits.
you were on this thread...rust encapsulant vs. por-15 ... giving advice on using por-15 and now you are going to go to their website and read the instructions.. Simon...Sim...i mean... Scott...Scott...Scott... ......
Finally, some PRODUCTIVE banter... I am cleaning and painting the engine bay this weekend, so I can leave the hood open.
Even though this is not productive discussion material for this thread... In the past, I have read POR-15 instructions for using it on metal, not on any other materials.