Unless the "crap" being "melted away" is the original black wax corrosion protection coating that Ford used to dip all the frames in (depending on year the truck was made). For those whose truck frames are wax dipped instead of e coated, it will be amazing how quickly the frame flash rusts after all the wax is hot pressure washed away. I think 2004 or 2005 is the changeover year from wax dipping to ecoating.

 

But the rust will be an excellent base for POR15.

 

 

I have a 20hp gas driven, diesel fired boiler, triplex pump hot water pressure washer lying around at home. But I can't see using it under the truck frame, because the hot water pressure washer wand is almost 4' long (too keep the operator away from the scalding hot water spray) and I would find that too awkward to work with, in order to see what I'm spraying at the same time as spraying it. But I'm just awkward in general, so that limitation would not apply to everyone.

 

 

The boiler in my hot water pressure washer is a coil. A long coil, essentially a wound up length of Schedule 80 steel tubing that cost me $1,000 to replace (part alone) when the original coil perforated in one tiny spot from corrosion. It took 5x macro magnification to see the hole, but it was enough to make a mess out of the pressure washer until the coil was replaced, which I did myself after getting the new coil shipped. I have no idea how hot the water actually gets when ejected from the spray tip... but the unit claims to produce around 294,000 btu per hour, and claims to raise the temperature of the inlet water by around 130F. So if the inlet water is already 70F, then 200F is probably about what I should be expecting, although I'm guessing 180 degrees is what I'm seeing as it leaves the tip, and that probably rapidly drops another 40 degrees as the water is atomized and aerated before it hits the surface being cleaned.

I have seen hot water pressure washers at the place where I buy parts that are newer than mine with a "steam" feature that claim 250F temperatures, so I have no reason to doubt the other poster who claimed this. I'm not sure how they work. I'm in enough hot water as it is.

 

 

 

8gpm at 3K to 5K psi, hot, is some serious cleaning power. At 6" close range, you've got to have some guns to hold the gun. I think my 20 year old truck would vaporize, right along with the steam. I might be better off with a toothbrush. My machine is only 5gpm at 3.5K.

 

 

Not a bad idea. I have a Snap On pressure blaster that I've never used. Been in my shop for years collecting dust. I'm going to look into doing what you did.