1967 M416 project (4 Viewers)

[The Jade Bean]

^^^ We're mostly men, looking at pics is what we do... Wait maybe that's just me.

-Daniel

Sent from deep in the mountains of Honduras using only sticks and rocks.

 

[BMThiker]

Worked on my trailer a bit. The tub is still at the sand blaster - I did tell him no rush.
got the frame painted. still need to do some touch up here and there. 99% done.

while paint was drying, I went to work on the lunette to make it a scoach longer. cut it in half, started cleaning up the surface.

forgot what the exact dimensions of the tube were, but this is 1/4" wall DOM. Snug fit after polishing the forged parts with a flap disc wheel.

The tube is 14" long which will extend the overall length about 8".

Fat overlapping helical welds

Terrible looking lumpy caterpillar weld going on here. I can certainly appreciate the art of welding that I see at ACC.

Next I drilled a 1/4" hole about 1/2" deep at each end and 180* from each other (4 holes total).

Then welded a "rosette" although mine look more like mushrooms compared to Dugan's welds. The idea is to pin the tube to the forged part by burning a really hot weld from the bottom and work your way to the surface getting wider and wider as you draw it up.

Prepped for powdercoating.

 

[maat]

you keep ragging on your welds but theres only one way to get better at it! and I think your heading in the right direction.. love the build so far

 

[BMThiker]

Thanks Maat.

 

[Mark Harley]

I like the lunette extention. I read that when welding cast iron, You need to heat up the cast iron
part before welding? I have never seen it done. So I am not sure why.

 

[BMThiker]

I thought that was true as well, but Dugan at ACC said to just give it plenty of juice (V) and it seemed to burn in really well.

 

[Mark Harley]

I like that you kept the tube small in diameter and not a big chunk of 2" square.
Nice work. It will look stock but extended.

 

[ntsqd]

I strongly doubt that the lunette is cast anything, much less cast iron. Wrong material choice for the application.
More than likely they are forged steel. Easy way to tell if the parting line hasn't been polished off. Castings have a very thin parting line (say 1/16" to maybe as big as 3/32"). Forgings are much wider (1/8" minimum). Once you've seen the difference it is pretty obvious which is which.

When the part being welded on is large it pays to do pre-heat and possibly a post-heat as well. What happens is that there is so much mass of the part that is at room temperature that it acts as a heat sink to the weld metal and HAZ. This effectively quenches the weld & HAZ which makes it brittle. By pre- and possibly post-heating you reduce this effect significantly. Placing the just welded part in some sort of insulator (dry sand, etc.) to cool down in further helps keep the brittleness from forming.

 

[BMThiker]

Yep, forged makes more sense, now that you point it out. Thanks for clearing that up. But no parting line is visible - this lunette (and others I've seen) get taken to a grinding wheel once the piece is forged to true up the dimensions of donut & hole. The telltale sign is a 3/8"-1/2" wide flat spot where a parting line should be. I feel pretty good about the heat applied to it. I went around it twice on each end. The first pass filled in the void pretty well. I then cleaned it up a bit with the flap disc and went over it again with the overlapping welds.

 

[Mark Harley]

Thanks! I learned something new today!

 

[yzftaco]

When you guys weld the reciever in the rear frame like that, what did you do about the tub mount that's right there? just get rid of it, or did you move it?

At least my M416 has a body tab to mount to the frame there.

I was thinking about frenching it in below it..

 

[BMThiker]

Actually, I've negated two tub mounts: one tab at the edge and the other on the cross member. Probably just going to cut the tab off and not worry about it too much.

One idea I've had in my head is actually mounting the tub 180* from the original mount position. The front wall of my tub and the corners are bent from previous owners. The idea is that if I'm going to cut a tailgate, might as well cut from the end that is messed up and then start with new sheet metal for a tailgate. Also, cutting that wall out will allow me better access to straightening out the bent corners.

We'll see. I think for now, it will just go back on normal, minus a few bolts. I've got a tarp on the way to use for a cover, until I get a lid engineered out and some more bucks in the bank account. Here’s what I ordered. http://www.mytarp.com/5x7-black-vinyl-tarp-22-oz.aspx

 

[Mark Harley]

I got the same material for my M101A2 cover but I ordered a MACHINE cover " like a shoe box lid"
that drops over the sides 5" Works well and keeps the water out.

 

[NGA-FJC]

Subscribed. Trailer is looking fantastic. I'd be glad to help, if you need anything.

 

[BMThiker]

Got the tub back from the sandblaster, and it looks pretty good. I had plans to reverse the tub so that my wrinkled end would eventually become a tailgate and thus cut away. However, after looking at it closer, I don't want to put that much into reversing all the brackets to make it happen, so I'm just going to live with the "beauty mark" that it has. The only defect that I wanted to address was the larger dent on the driver side of the tub. It was big enough to impact the engineering of a future lid. This was remedied with a portable hyraulic piston. I pushed against the front passenger side corner for leverage and it did the trick without pushing the whole tub out of square. Also chiseled out the years of paint in and around the drain plugs, since the sand blaster did not work well in those tight areas.

now for some pics!

My custom lunette

the beauty mark

the dent to be re-aligned

cleaned up the reflector bezels

using the portable piston to push the dent out.

happy with the results

 

[Brian in Oregon]

Do you have in-progress photos of your lunette conversion?

 

[Mark Harley]

Looking Great! Great that the pushed in side smoothed out.
Looking forward to seeing more work.

 

[BMThiker]

Do you have in-progress photos of your lunette conversion?

POST 22 above.

 

[BMThiker]

Made some good progress this weekend. Sprayed the whole tub with an etching primer after scrubbing it with degreaser/solvent and red scotch-brite pads.

Then rattle canned the whole thing using Rustoleum CAMO series...Forest Green (iirc).

used Rustoleum Wheel Well liner to coat the bottom of tub. Probably will do inside the fenders with the same stuff.

test fitted but not bolted back together. Still have to clean up the wheels/tailights and paint to match. Also plan to reinstall all the OEM ID plates and reflectors.

Still, not bad when this is what I started with.

 

[Mark Harley]

Very nice end result!