Galvanized Frame question (1 Viewer)

[BRShap]

How brittle? Isn't the dip only at 800 degrees? Thats hot enough to affect the steel?

As Splangy alluded to this is really only a concern with very high strength steel alloys and only in certain conditions. 800F is no particularly hot for steel. You can start to see recrystallization closer to 800C.

Long story short I very highly doubt that galvanizing a FJ40 frame would damage it in any way and I don't know why shops would cite that as a reason to refuse the work.

 

[Michael B]

There will be considerable buildup in all bolt holes. Usually drilling the holes and retapping them is all you need. It's time consuming but not difficult at all.

In most cases if you deliver the frame early in the morning the unit is ready to go that afternoon. I would suggest an earnest conversation with the intended vendor prior to arrival.

 

[ryanwk628]

The only concern I would have is if the vendor has tanks large enough able to accommodate your frame. My company had some large weldments that were designed to be extremely rigid and the galvanizer dipped it one half at a time because their tanks were too small. That uneven heating caused enough thermal expansion to literally tear the weldment. An outfit that does plating of small parts like the yellow zinc stuff fasteners may not have large enough tanks or an overhead crane to do a full frame.

 

[3_puppies]

I recall a write-up that detailed this in Toyota Trails. The person used sacrificial bolts to protect the threads during the process. Some of the bolts broke during the removal process and the solution was to heat the bolt long enough to soften the zinc before extracting the bolts. Can anyone else comment on this?

I vaguely remember that article, what was it, 20 years ago?? late 1990's. IIRCC it was still in the black and white days.

 

[Jetlander]

I figured this brittleness issue was all hubbub and not going to be much of a factor. Interesting about the risk of only dipping half the frame at a time though. I hadn’t thought about uneven heating twisting the frame. The size of their tanks is definitely something that should be asked of the vendor.

All good info. If I can find a place to do my frame I’m putting sacrificial bolts in. I planned on running them only as deep as the threads, hoping they’ll be easier to get out.

 

[SuperDuperCruizer]

@3_puppies it was the old black & white days of Toyota Trails. I probably still have some of those issues boxed up some place. The tech information back then made Toyota Trails such a valuable resource.

 

[3_puppies]

@3_puppies it was the old black & white days of Toyota Trails. I probably still have some of those issues boxed up some place. The tech information back then made Toyota Trails such a valuable resource.

X2. I would need to find the box. I got many years worth of old trails mags from a guy I sold a bunch of parts to many years ago. I'm thinking that was 10+ years ago. WOW, time goes by fast.

IIRCC the original article was done by a guy in Alberta Canada??

 

[Weber Sarge]

I'd honestly leave the bolts out - buy the correct metric taps and be prepared to replace them as they dull. Even with good cutting fluids (some can attack the zinc) they won't last long. Removing a jammed bolt with coating is no fun and you may damage the coating around the bolt hole by using heat. I'd try to use TD Foamy for lube, it seems less invasive to paint and coatings and with decent quality HSS taps it should take about a day to do the job. I would not use a drill, that zinc can bond itself to cutting tools - it's known to kill off drill bits for that reason and tapping should probably be done by hand, unless you have a lot of experience.

In the metals thing - I see no reason if they can hold the temperature no higher than 800*F that it would damge the frame. It may slightly warp it , but once you start assembly after the curing time it should easily go back to where it was. You could weld a sub frame up and use the main body mounts to stabilize the frame , then toss it after the thing is dipped but any contact points would have to be touched up afterwards.

Sarge