cleaning inside of frame?

[mavereq]

i am working on a bare frame that has quite a bit of rust on it and plan on taking it to get sandblasted eventually. will they be able to get the inside of the frame clean, or is dipping my only option if i want to make sure the frame doesn't rust from the inside out?

 

[J.K. Francis]

I just went through this with mine. I went to one of the big box hardware stores and bought a six inch chimney cleaner with a couple of fiberglass extention rods. I cut down the diameter of the brush with a pair of dikes and ran it in the frame rails till I was satisfied. I have only done the rear half...
Then I took an old garden sprayer and rigged an extention rod (about 6 feet) and sprayed the inside with Ospho a couple of times. After that dryed, I used the same sprayer and sprayed the inside with Rust Bullit. That's the part that didn't cover as good as I would have liked. That pump up sprayer just woulddn't produce a good spray pattern. If anyone has a better idea on how to spray it, chime in.... Jeff - VA Beach, VA

 

[bax]

Hot dip galvanizing. Best way.

 

[tasker]

i did the chimney sweep thing as well, then took 3/8" steel brake tubing and joined them together with the end bent and hooked to my shop air. Blew all the residue out nice and easy.

 

[NicksTrix]

chem strip then galv. absolutely the best and easiest.
with it chem stripped it gets all rust in the overlaps and all the nooks and crannies. the hot dip galv does the same thing. you'll need to retap very hole you plan to use since the threads get filled up.

here's shots of some. before, after and during repair before hot dip.

the chem strip process will remove all the rust cancer cells, so there is nothing growing anylonger. after it's done you see exactly where you need to repair.
after it's chem stripped they Ospho it so it doesn't flash rust.
the glav shop i use their process is run it first through a blast tunnel if it needs it, quick acid bath (not as intensive as chem strip) then into the hot galv then quench.

 

[nrramse]

Hot dip galvanizing. Best way.

What's a reasonable price for this?

Newell

 

[tasker]

very cool Nick, again what's a going rate?

 

[trailpsycho]

A single Bronco frame is about the cost of a standard "set-up fee", if you can get a few frames together, you can get the cost down a little. A set-up fee will vary depending on your area and the company, but should be in the $300-350 range. I havent talked to my buddy about how much the prices have gone up since mine was done about 4 years ago. North American Galvanizing has a plant in Nashville, TN for anyone in the southeast. But there are others, as well...but those guys will do a great job for you.

It would be advisable to have the frame blasted inside and out (or dipped as Nick mentioned) before it is taken to be dipped, in fact, they wont touch a fouled up frame. The other point to make is that ANY and ALL modifications, welding and attachments should be done between the blasting and the galvanizing...or pre-blasting. You dont want to have to weld onto the frame after its been galvanized.

If you do a search, there are several other threads about cleaning, treating the inside of the frame and galvanizing, including some pics.

Good luck.

 

[mavereq]

sweet. nashville isn't too far. heck i drove up there to pick the frame up in the first place. i'm working on the welding right now. i wonder if north american galvanizing can do the chem stripping as well. that would make it a one-stop shop and really convenient.

 

[trailpsycho]

No, they dont do chem stripping. They do a dip, but its a "pickling" dip in acid that does a final cleaning of the metal. However, the steel should be clean before it goes to the galvanizer. Sandblasting works great...and they can get pretty far into the frame...if you have major frame repairs, consider having it blasted before you do your repairs. Keep the frame inside and dry and you will be fine taking it to the galvanizer without a second blasting.

Another thing to consider thats actually pretty important. If you have any aftermarket tubing (frame tie-ins for cage, tube-style shock mounts, etc) welded to the frame, then you need to drill 3/8" holes in them at the top and bottom. As the "work" goes into the molten zinc at ~800 F, any air inside any tube or closed space will expand and can/will explode. The holes allow a way for the zinc and air to flow in and out. I had both types of aforementioned tube accessories on my frame and we had to drill "drain holes" prior to it going into the process. YOU need to take care of this...its not the galvanizer's job. We ran out of battery on the very last hole...very lucky....start with a 1/4" bit and then open it up to a 3/8". Its easier/faster on both you and the drill.

If you talk to Mitch or Mike, tell them you heard about the plant here and that I sent you.

http://classicbroncos.com/forums/showthread.php?t=146796&highlight=galvanized+frame
http://classicbroncos.com/forums/showthread.php?t=129063&highlight=galvanized+frame

Good luck.

John

 

[mavereq]

thanks for letting me name-drop. i can just tell him that john from indy sent me. do i need to know any secret handshake?

i took some vacation time to get ready for my fight next weekend and to work on the bronco so hopefully i'll have everything welded up on it by the end of the week and can take it up there next week. i'm waiting on my johnny joints to come in so i can finish fabbing up my radius arms and then once i get my new coil spring buckets welded on i should be good to go.

i'll go ahead and beef up the frame horns now just in case i decide on some heavier bumpers.

 

[SwedenBronco]

Last week I cut up an old Wrangler frame that seemed very rusted out, but inside the center sections of the frame rails, except were the belly pan treads were, there were hardly any rust at all, you could still see the blueish color after the seam welds of the frame rails, I was surprised to find out that those parts were still in the shape they were compared to the rust/shape on the outside of the rails...

 

[76 bronco J]

>>>>> a zinc cold galvanizing spray or zinc weld through primer might be a option for those not doing frame offs.... while no where near as good as hot dip even though some try to claim that, it seems to keep rust at bay pretty good.... the zinc's sacrificial nature seems to offer some protection even without 100% coverage such as spraying the inside of a early bronco frame ...... I had a boat trailer before with a box frame & it cracked in half from interior corrosion while the outside looked great...........

 

[J.K. Francis]

So what's a good spray rig set up to spray the inside?? I can't seem to come up with one........Jeff - VA Beach, VA