Slowly working through taking the '61 down to bar metal and then DP Epoxy Primer. I know the Phosphoric Acid treatment isn't absolutely necessary but trying to keep the Flash Rust at bay until can get to primer and original steel has pits rust converter might help. I get different results with the Phosphoric acid using same directions. Directions say to keep applying acid (keep wet) for @ 15 - 30 min then wash/remove thoroughly with water. > When I rinse or wipe with wet rag, the bare panel will rust as I wet it. Any better method or explanation of using Phosphoric Etch ??? Applying acid lightly and let dry seems to leave reasonable clean etch-toothed surface for paint , but directions say to wash off ? Please no anti-Ospho rhetoric ... Thanks CLeaned and etched: DP Primer :
Where do you live, you probably live in a very humid area. In your case what I would suggest is let is dry for 24 hours, then DA it with a 120 grit, wipe it down with wax grease remover, prep it, etc.. I do is the exact same thing you did if I am going to primer it right away, if not I brush it on and let it dry until I am ready to primer, then wet it down with acid again to remove the white stuff that dried on it, scuff it with stainless steel pad, wipe it down with water, then prep for primer.
I don't know your location, but I've been using Bill Hirsch's rust preventive spray over bare metal and it keeps flash rust/rust at bay until I can get paint on it. I've used the phosphoric acid stuff but as you note, it only works in certain cir***stances. The Hirsch stuff also must be cleaned off but you are going to do so before painting anyway. It can get wet and retain it's coverage. It does have a sticky feel to it but I've left parts months without any flash rust. PM for more details as I stock his stuff.
This is brushing it on and leaving it for later, half is rusty other half is treated. This is adding the acid again and scrubbing it down, top half is scrubbed down, bottom was left with acid for a few weeks: It seems you are doing is right, but probably not letting the acid work long enough IF you do live in a humid area. Again I suggest letting it dry completely, when you do that it will leave a protective coat of zinc oxide on the surface, that way if you add the acid again and wipe it down with water it will not flash rust right away.
After you hit it with water .dry Then immediately wipe it with laquer thinner on a rag .This works for me
When I worked at Redi-Strip long ago when we did the final wash out of the de-ruster tank we had a setup to allow the pressure washer to siphon phosphoric acid out of a barrel, we had a control valve to limit how much phosphate got mixed into the fresh wash water, it worked the best when the it came out of the pressure washer looking like soap that you see at a carwash, plus the 200+deg water made it dry almost instantly, but in cases when we had to apply it by hand when someone would touch the bare metal with their bare hand(s), if I remember correctly we used a 7 to 1 mixture of water, and phosphoric acid wiped on by hand and let it air dry to prevent flash rust, when it was time for primer we told the customer to wipe it down first with lacquer thinner (I would suggest you experiment on a test piece to make sure that it works, and that the primer will stay on the metal). Hope this helps.
Thanks for the replies, 53Choptop's similar results but with more experience sounds about where I'm heading. Letting phospho' dry with rag application leaves enough to keep flash rust at bay, and then when ready for paint, wipe again to smooth dried oxide, scotch brite for rough etch spots , wax/grease wipe and then primer. Here in the N.E, Mark Twain said something like, " If you don't like the weather - wait ten minutes" . Rain and storms roll through the Hudson Valley with regularity and humid days can alternate with dry... Have Fun
i've had good luck with LPS 3 as a bare metal protectant. wax and grease remover takes it right off , just soak a rag and go side to side.
Yeah I have used this stuff for a long time, as you can see in my hand in the pic, when they use to sell it in convenient spay bottles, I have learned to avoid the spray bottle technique, this stuff is nasty when inhaled. In the beginning I mostly learned how its NOT suppose to be used and what it does to paint, filler (which is what I learned in this pic: filler+acid=bad filler), chrome, stainless steel, and gl***, but once that learning curve is out of the way, learning how good it is when used right, its an awesome product.
Just a thought...are you sure that what you are seeing coming back is rust, iron oxide? If you removed all the rust with the Phosphoric, (that is, all white metal, no dark spots in pits or anything) what you might be seeing is the formation of iron phosphate, which is good, not bad. It will protect the steel temporarily, and makes a good base for primer.
what Chopolds said.... One test is to leave it till dry (after washing with water) - I like to towel dry mine and add some soda ash in the rinse water - very acidic borehole water here .....but I digress. Once it's dry, if the yellow stuff transfers to a clean cloth when rubbed it's flash rust - if not it's iron phosphate. Now the question is whether you're gonna trust that advice under a high dollar paint job....
Alright, please speed up my learning curve - What does it do to Gl***, stainless and chrome ?... Thanks Gettin' there...
I used the Metal Ready product on my F1 frame and also the bed, washed it off with water, worked perfect. My biggest concern was missing any nooks and crannies with the phospho, and then the water hits it and makes instant rust.
The Jalopy Journal
