De-rust + Paint cross-memebr tube ideas? (1 Viewer)

Oct 28, 2009
NOTE: editted down, just found post about Eastwood Frame Interior ... why didn't THEY mention it when I spoke to them on phone? Would still like to de-scale the interior of the tubes prior to spraying.

75 FJ40. Working on de-rusting / painting the frame. Frame rust is pretty bad, with heavy scaling all over, but no rust-through. Wire-brushing most by hand and with standard power tools, & I made extensions for the hand wire-brushes to get up into the enclosed sections of the frame rails, so, that's under control. But, have run across a conundrum.

2 (2" Dia?) frame cross-member tubes are not only small & long, but have nice (expanded "U" - about 2.5' tube length) bends in the middles of them. Any ideas on how to de-rust the interiors, and how to get paint products in there?

I don't have a sandblaster, and am out in the boonies, so - for the moment, that path looks like a non-starter. The thoughts that I'm having are to try to locate big-a** tube or flue brushes (Where's Dick van Dyke when you need him?), run a line across, and then run back and forth yanking on the ends of the line to scrub out the scale.

So, anyone with experience getting the insides of the tubes ... I'm looking for ideas. (If it has to be sandblast and sprayer with extensions, then, at least that's an answer).

Last edited:
Jan 25, 2007
Lincoln, CA
well i just used this process on my rear doors... you could try it too - i used a rust converter (they're all the same it should say it leaves behind a black surface that is paintable/primable got my stuff at lowes but NAPA has some too) I then capped all the holes in my doors after pouring it in and shook it around for about 2 minutes. don't know how you're goign to do that with a frame though... maybe rig up some spray system with a hose that has holes in the side every couple inches and pressurize this stuff in there? if you use this stuff just make sure to prime and then paint inside since doesn't prohibit rust

also there is products like this
that you could try
May 3, 2009
Your basic two-man approach sounds good. Try wadded up emory cloth, steel wool, basically everything until you feel you've gotten things to a state you're comfortable with. Wipe the tube out with an alcohol saturated rags to de-grease. Then use a rust converter and paint or POR-15 to seal it all up.
Mar 4, 2007
link 2 or three, cheap drill flex drives (Home Depot or similar) with a flapper wheel on the end. insert into the cross member tube and ream it out. then spray with your preferred product.

As for the frame rails: Pull the bumpers and brackets; This will give you some access. get a fiberglass rod (small diameter (Kline flexdrive/puller kit) install assorted tips. even lead weights on a leader (slings around into crevices) Get it as best you can the por 15 it with the Easton or similar interior surfaces spray tip. NOte: HArbor freight, norther & southern tools have cheap spary set ups. Used to be under a $100.00 for a starter kit.

Best of luck. I'm not a body guy just resourceful when needed.
Feb 10, 2010
i had one of those wire brushes you mount on a drill, with a flex drive and spun it up with my die grinder, cleaned all the rust out, i then acid washed the entire frame with a pressure sprayer, let that sit for an hour to soak then pressure washed it all off, where ever i missed it has fallen off while sitting there for the last 6 months, i plan to pressure wash again to get the rest out, then coat all the inside the frame with cavity wax,
BTW the acid i used was very very dangerous mix of hydrochloric and sulphuric acid, use the proper PPE when using this stuff, IT EATS SKIN
Oct 28, 2009
Great Ideas ... Thanks for the replies ... Found various flexi-extensions; gonna try them first (With a little trepidation ... many reviews refer to, "... if it hangs up, the tube becomes knotted ..." ... a little worried about it getting stuck in there) ... Probably have the "2-man" (Me & Myself) set-up ready as a back-up.

As for the HCl + H2SO4 approach; yeah, I've worked with both ... probably not going to go that way. I appreciate the lead to Harbor Freight - I usually avoided them, since reading a lot of bad reviews on their stuff, but, frankly, for that cheap, if it works long enough to get this project done (at those prices), then ... works for me. (+ They list a 600 Ft/Lbs air hammer for under $100 with (all) 11 great reviews, so ... I'll have to add that as well). But, an inexpensive spray set-up will definitely help to get product inside those welded nooks and crannies that can't be gotten at otherwise!

As for how to treat the insides of the tubes ... this just dawned on me.

First, clean the tubes (at LEAST THE ENDS) so as to give a good surface to get a good seal.
Stuff a rubber plug into the (driver-side) ends of the tubes (i.e. - engine freeze plugs of the correct diameter), or otherwise (somehow) SEAL the (driver side) tube ends TIGHT.
Then, elevate the other side, HIGH! (Ummm ... guessing the Passenger / gas cap side is the better side to lift; on a high curb, ramps, or Jack it - the higher, the better).
Dump in as much rust converter into the off-side of the tube as it will hold, and seal the passenger side the same way as the driver's side.
DRIVE! The bumpier, the better ... slosh that stuff around in there for a WHILE! (If leaving it in for a while, maybe repeat the driving process periodically).
Drain, and re-use the stuff to repeat on the other tube. (MetalRescue & some of the others claim to be re-usable; at least a few times).
As for the paint ... well ... There's multiple ideas here on the page ...
Some may call that "excessive" but, if you saw how scaly my frame is (while still save-able, without cutting and welding ...) You'd understand. A gallon of MetalRescue is only $25 (although, my tubes MIGHT need 24 hrs of soak, and may not be able to re-use the product after the first tube).

I just figure that my frame is at a critical juncture - done right, it can be saved, and be great. NOT done right ... I'll be cutting and welding (IF there's enough frame to weld to) in the next few years. (BTW - we're a "salt the roads in the winter" state).

Thanks (ALL!) again for the replies / ideas. Gives me more confidence, and a few additional avenues.

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