Frame rails

[h67st]

Well, I got some more brackets and such removed and I found some heavy rust on the frame rails. They will probably suffice since this will just be a hobby truck, but I'd  really like to replace them...does anybody know where I can get new or good used rails for an H67 tandem? I don't want to splice them. Second question: how do you remove the buck rivets in the crossmembers? I cut the head off one but the shank is swelled in the hole so it won't drive out.

[Truck Shop]

Heat the center of it then nail it with a large drift and 3# hammer or heat and use a air hammer. The best way I've found to remove rivet heads is use cut off wheel and cut a X in the head down to the shank and use a very large chisel, the heads will pop right off.

Truck Shop

[Swishy]

Why bother with new rails for a hobby truck

just sand m down heavily in the rust area n a few layers of paint splashed on n only U n eye will kno the difference

WotSezU?

cya

§wishy

[carlotpilot]

They will come out. Just takes a bigger hammer.

[topo]

Quote

When  removing lots  rivets grind off the head on one side  drill 3/16 hole 3/4 of the way through the rivet then go back and drill them out to 5/16 use a 1/4 inch punch this will let the rivet  collapse to the inside  with larger rivets go with a larger hole till you find what works

 

[h67st]

12 hours ago, Swishy said:

Why bother with new rails for a hobby truck

just sand m down heavily in the rust area n a few layers of paint splashed on n only U n eye will kno the difference

WotSezU?

cya

§wishy

I may do that; it's not the appearance I'm worried about. The rust is really deep, like half way or more through the metal. In some spots it's right in the radius of the flange which is a bad spot for cracking.

[terry]

If you are going to just bobtail around or even lightly loaded i don't think you will ever have a problem, once you get old rust out and seal it good.    terry

[kscarbel2]

If you go with the present frame............

Ospho (phosphoric acid) is a rust convertor. When the acid reacts with iron oxide (rust) it forms iron phosphate, turning the metal black (the iron phosphate). You then REMOVE the Ospho residue (even though their direction say you can paint over it - some primers will not stick to it because it is too acidic and they won't cure properly [ask me how I know]) and then paint over it with primer. The best procedure is to use a wire wheel or sandblast the rust down to bare metal and treat with Ospho, remove the reside (with soapy water) and then prime and paint.

http://www.ospho.com/

POR-15 is a rust encapsulator. It does not convert the rust to anything. It simply encapsulates it in a REALLY hard paint shell so no oxygen can get to it, thus stopping further rust. POR-15 has a very specific application procedure and works best on rusty, but well-prepared metal (wire brush off loose rust, use their Marine Clean to clean it, treat with their Metal Prep solution [if smooth or new metal], paint with POR-15). If the metal is too smooth (e.g. wire wheeled smooth as opposed to sand blasted, which leaves it rough) the POR-15 will peel off like electrical tape (again, ask me how I know). POR-15 is also not UV safe - it will turn milky and chalky from sunlight.

Which to use depends on what you are trying to do, how well you can prep the surface, how you can apply it. For rusty frame rails you can do either but it might be easier to use POR-15, though it will probably cost more. That stuff is expensive. They do have some new products that apply over POR-15 rust encapsulator, like chasis paints (to provide UV protection). If you topcoat it, you have to do it before it cures or else sand it, which is almost impossible.

http://www.por15.com/

POR-15 is for bare or rusty metal. It won't do any good over painted metal, and probably won't stick. It has to bond with the rust/metal to seal the rust. So make sure you get all the paint off the frame.

http://www.toyota-4runner.org/3rd-gen-t4rs/136894-por15-vs-ospho-show-down.html

 

[Maddog13407]

I have drilled straight thru the center of the rivet after you grind the head off. drillin a 1/4 hole thru the center sometimes relieves the pressure then heat around the outside with a torch to expand and get a BFH out

Edited July 11, 2017 by Maddog13407

[Brocky]

To add to the excellent information from KSC there is another product made by KBS Coatings which similiar to the POR-15 which can be applied with a brush and when dried looks sprayed. Contact Eddy Lucast at Eddy.Lucast@remotedata.com or here:  http://kbs.justoldtrucks.com/

[nwfs600]

When applied correctly POR-15 is hard to remove. I restored a Formal H years back. The top of the fuel tank had been covered by Por-15. I ground with 36 grit on a 7 inch sander for days to get it off.

[fxfymn]

Chassis Saver is another POR-15 type product that works well and sells for less than POR-15. Available at Magnet Paints.

[Keith S]

On 7/9/2017 at 9:15 PM, h67st said:

Well, I got some more brackets and such removed and I found some heavy rust on the frame rails. They will probably suffice since this will just be a hobby truck, but I'd  really like to replace them...does anybody know where I can get new or good used rails for an H67 tandem? I don't want to splice them. Second question: how do you remove the buck rivets in the crossmembers? I cut the head off one but the shank is swelled in the hole so it won't drive out.

Heat is your friend... lots and lots of heat. Hot and cool cycling the rivet will breakdown the rust - air cooling between cherry red is fine. And a hammer... a BFH (big f...ing hammer) and punch.

Sandblast the frame. Or, if you have a lot of time, ear protection, and strong hands, an air "pistol needle scaler" works great on a frame. To see how much work is involved you could try Hazard Fraught, but the needles won't last long. Don't buy the cheap replacement needles.

I'm not a fan of POR 15 or any rust encapsulation. If you go the POR 15 route, spray it, and two coats.

 

[steelman]

I am not too wild about using heat on the frame, as it is heat treated.  Same reason you should not weld on them.  I have a 1918 truck frame we took apart last year to replace a frame rail, rivets and all.  We cut the heads off one side with a cutting wheel in an air powered tool first.  We then took an air rivet tool with a punch in it, and pushed them out.  It wasn't easy, and it was loud!  A few that seemed stuck we drilled out the center of the rivet as described above, then used the air hammer on them and they came out. After that, I cobbled up a 70 ton hydraulic tool to push the rest out, using an old punch and die (we are a steel fab shop).  Like I said, I am not fond of heat for this application.  We did use heat to put new rivets (5/8" diameter) back in when we put it back together. We heated the rivets up to cherry red, put them in the hole, and banged away on the other end, just like they were put in originally. Just my 2 cents worth. 

[Keith S]

I sort of agree with no-heat - if it's a new truck. But when the whole project is considered I suggest that 50 years of rust, load-stresses, vibrations, accidents, unknown repairs and methods of repair, frame straightening with big hammers (thinning the material), lots of heat and a lot of bending force... will have a bigger impact on the material strength than localized heating of the rivet & area. Unless there is documentation, it's really hard to determine if something is heat treated or it's simply a high-strength material.

Auto companies use high-strength steel and anticipate accidents and damage repair, so they make accommodations with welding guidelines. Mack Body Builder instructions also show proper welding and modifications to the frame/chassis.

With repairs and restorations and with unknown history, everything thing is a comprise. Seldom is an old vehicle "correct" and unmolested.

[h67st]

Keith, is that brown liquid in the cup a special rust-eating chemical?  ;-)

I decided to try the drill method; I was surprised at how easy the rivets drill. I started with a 1/8" and stepped up to a 1/2" bit, I kept the drill slow and lots of oil--it went fairly quickly. Chiseled the head off and the body popped right out.

[jackb61sx]

When we did our restoration on my B-61 we made up a punch with a long handle for one person to hold and a large flat spot to hit and I would stand on the frame rail and take full swings with a sledge hammer and just drive them out of the frame and they would fly out when hit naturally we had ground the heads off first. Those that where tougher we drilled out with a magnetic drill. Our frame was pretty pitted when we took the triple frame apart and the parts of the frame that would be seen the inner and outer frame after piming we filled with body filler and sanded and the frame is like glass now. 

[Keith S]

Good'ol rust. There's a sense of satisfaction when using a needle scalar - for about 20 minutes. Then you realize you have several hours of dust and dirt and paint and... But, a lot cheaper than blasting. It would work great on your heavy, scaly rust. Good on cast iron too - That's how I found multiple cracks in a rear hub.

https://www.flickr.com/photos/emack/34284586933/in/album-72157684558130216/

[Vladislav]

On 12.07.2017 at 2:24 PM, h67st said:

Keith, is that brown liquid in the cup a special rust-eating chemical?  ;-)

I decided to try the drill method; I was surprised at how easy the rivets drill. I started with a 1/8" and stepped up to a 1/2" bit, I kept the drill slow and lots of oil--it went fairly quickly. Chiseled the head off and the body popped right out.

 

The rivets are made of low-carbon soft steel. To be shaped up by pressure. That's why you (and me either) drill them easyly.

When re-riviting my frame I ordered making new rivets in a machine shop. Had to buy a stock of sutable steel for, being guided by general recomendations on that matter.

https://www.bigmacktrucks.com/topic/29254-frame-is-ready/#comment-155896