R-model cab resto report

[Vladislav]

2 hours ago, mechohaulic said:

not only where you lift from;  biggest concern  - what  is being used to lift  the cab.  towmotor (forklift) , overhead chain hoist etc all make a difference.  did a few B-C-R  conversions back in the mack  days with forklift.  couple of mysterious  fire jobs on B model  ten -wheelers. with dump bodies still on clearance was a minimum .  nice set up in the pictures with over head  hoist 

When i built the building (and actually it will be built more upwards in the future) I put 4 U-channels and welded wiring to them and connected to the main slab mesh. So they are both integrated into the slab to increase its load capacity and allow to hang sufficient loads on the hoists. Currently i made two cross beams in the half where the truck was parked to dismantle engines etc and only one so far at the right where the cab was lowered down. The matter to make 3 was the length of the beam I bought for - 12 meters gave me 3 parts of 4 meters.

[mechohaulic]

real nice job. I HAD a 30x50 shop  as seen in some of the pictures posted. not massive, but for a residential  neighbor hood I got away with a lot. when the concrete floor was poured  (6in thick) I  made  two 3ftx3ft steel I-beam frames  which had large clevis in middle.  access to clevis after floor was poured was through  12in  flush mounted cover.  one at each end of building. use them more than expected.  straightened bumpers and more. was able to pull down  with chain hoist. no way was the floor picking up.

[Vladislav]

Part 2.

After bringing the blasted cab shell into a warm shop I investigated some stress cracks which were not seem or notable when the cab was still in paint. Welded those cracks and also holes we created drilling some spot welds. Had to cut off a piece of floor around the area of the driver seat front mount and weld a patch. There was extensive corrosion and plenty of tiny holes showed up after blasting overthere.

Edited March 5, 2020 by Vladislav

[Vladislav]

Further investigation lead me to one more unpleasant point. Rust sandwich was discowered in a spot weld seam where the firewall was mated to the right part of the cowl. You could not see much of it since the seam was covered with sealant and showed nothing of what you would be worry about. Blasting made 2 or 3 holes where metal was acually very thin and opened rust which took place between two sheets and already grew quite thick. We cut pieces off the both sheets making one opening longer than another. Welded 1st putch into the firewall and ground weld off on both surfaces. Than welded the second patch. I put it a way the long seam occured being not covered by any element from the inner side so we had access to grind it. Only two points of weld which were not possible to grind from the back appeared at the ends. For that reason I put those two patches not touching each other but having a gap of 2 mm between. All the seam will be covered by poliurethan sealer so no trouble with geometry and look. But the gap allowed to protect steel and weld with etch primer and further will be filled with sealer completely. The weld spots you can see on the final picture were actually not welds but local depressions I made hitting the patch with round drift. I made them on a bench, before welding the element in place. And that was done just for a look.

[Vladislav]

Next step was working out a plate, actually a patch to cover the rear cross channel from below. I cut a rusty piece of the floor sheet from there so needed a replacement. Steel shop fabricated me a stepped plate because the floor also had step there. I cut its rear to form a curve following the cab rear wall shape since was originally lazy to figure the radious when draw the sketch. Than we had to drill an uncount amount of holes since the idea was to attach it to the floor and the channel flanges by small screws instead of weld. That way it could be possible to paint both the patch and the channel inside before the assembly and putting them together with screws and sealer to avoid steel and primer burn out at all. Getting further I say I liked the way and the result but the amount of labour involved was 3 or 4 times more than just to weld. There was also a reinforcement plate put below the rear channel to accomodate the cab support airbag assembly. By the factory design it was welded to the floor. But as long as I avoided welding I used bolts and nuts. Had to weld nuts to the opposit side of the floor patch since will not have access to them when the patch is in place. Sure welding the nuts is also welding but the patch was planned to be blasted and painted before putting in place. So that weld will not be a burned primer spot and no potential rotting is expected.

Edited March 15, 2020 by Vladislav

[Vladislav]

Next task was to redo the floor support channel we cut away due to rust between it and the floor. It was a simple U-channel with 4 holes which correlate with seat front mounting holes in the floor. Actually that channel supported seats and carried driver's weight so seemed as an importatn element. The part was fabricated with no troubles but I needed to organize its attachment. Again, no weld where you cannot blast and prime/paint it. I made different fitments at two ends. At the passenger side I welded a plate to the end of the channel and drilled two holes for 5/16" bolts. Than drilled two holes in the cab floor side plate (something like a inner side of RH rocker) and welded nuts at them. The cab was planned to be sandblasted again and with no rockers in place. So those nuts would be opened for sand and primer. At the driver side I could not attach the same way for some reason of final assembly I already forgot now. Appologizes. Made a bit different fitment welding a piece of U-channed to the LH rocker inner wall. You could put the reinforcement channel onto that small part. Drilled two holes where they were overlapping but didn't weld any nuts since possible to just put them there and tight with a wrench at any time.

[Vladislav]

Found one more unpleasant point. There was a plank welded to the front edge of the floor opening. Actually to the lower edge of the firewall. When you put removable part of the floor it lays along that line so the plank was a reinforcement. The plank was spot welded at the factory and rust grew up in the gap. My helper drilled  off one more nightmare of weld spots and removed the old part. The replacement was also fabricated together with other new parts. We put it onto the cab, attached with vise grips and drilled multiple holes both through the plank and the firewall. Than the most interesting nuance. I put 1/4" machine screws into the holes in the plank and welded over their heads at the outer side. Than my helper ground all that together with screw heads to make the surface smooth. That way you could put the plank in the place putting the studs (former screws) into the holes in the firewall and drive nuts onto them from the inside of the cab. No weld and the nuts will be covered with removable floor of the cab when all is assembled.

[Vladislav]

One more element - welded togeter 3 new reinforcement parts of the floor. The big one is to support the airbags assembly will be attached with 8 5/16" bolts to the floor rear patch. Two longitutional members had holes at the front ends. I welded 4 bolts into the U-channel flange so after the channel is in place you put that 3 element assembly and attach it to the U-channel at the front by 4 nuts. The last pic is all the floor reinforcements in place and the removable part of the floor test fitted.

A cherry on the top of the cake - all bolts, nuts and screws were SAE, bought in the States and delivered by post

Ok, seems enough for today to post. I'm getting afraid the readers would get upset enjoying my English more than me when I jumped around the cab putting reinforcements to the floor.

[navypoppop]

Vlad,

Love your dedication to detail and making this remodel a work of art. It is very impressive to see your great work and your ability to do it yourself. I can't wait to see the final result.

[j hancock]

Good job on all the details!

[hicrop10]

You are doing a great job Vlad.Your attention to detail is fabulous.Hope my b87 turns out as good.

[Vladislav]

Got to the rockers. After some tinkering and a few nights of figuring I resolved to cut off a section off the rear end of the new part and connect it with that section of the old one via steel insert. Draw a kind of a U-channel with another U cutout to correlate with a big hole the original part had. Actually that hole is hidden inside when everything is assembled together but I wanted to minimize differences in the original look or style of the parts. Also there's a smaller hole in the outer sector-shaped "cover" which had a plastic plug and used to spray wax inside. And when you spray you get deeper through that big hole so there was also a reason to keep it.

Edited March 15, 2020 by Vladislav

[Vladislav]

Ok, ordered the inserts laser cut and bent together with other fabricated parts. Bent the corners myself to the final fit (originally ordered them with 90 degree bend for simple draw). Put new rockers in place, attached with vise grips and drilled holes everywhere i needed them to. After that removed the inserts and welded 5/16 hex nut at every hole on the inner side.

[Vladislav]

Put inserts and than new rockers back in place for the test fit. Drove all bolts and screws in the holes and used nuts where I had access to tight them up. Than took my breath away...

Edited March 15, 2020 by Vladislav

[harrybarbon]

Hello Vlad, your excellent work demonstrates your passion and dedication. Given the extensive work you are doing and your local weather seasons, may I suggest that you consider applying the LIZARD SKIN products to all the cabin body panels that are not the final painted panels.

I have posted here about LS before, the LS will be a 100% cover and protection in all the metal joints, welds, hidden sections as long as you apply it properly following the instructions. After you have completed all the repairs and there is zero rust, then first you have to apply primer to all the metal surfaces to seal the metal. Then you proceed to apply the 2 LS products, 1st the sound control and 2nd the LS. 

If you want a smooth finish on the fire wall facing the engine, I can give the process to achieve this result and I can send you pics of our B model cabin when we applied the 2 LS products.

Then you will not require any other applications for sound and heat and metal protection, only your painting products for the external metal panels that you see. And you do the 2 internals of the doors, especially the bottom sills which rust easily. 

Have a look at the LS web page for more information and videos. Good luck.

[Vladislav]

8 hours ago, harrybarbon said:

Hello Vlad, your excellent work demonstrates your passion and dedication. Given the extensive work you are doing and your local weather seasons, may I suggest that you consider applying the LIZARD SKIN products to all the cabin body panels that are not the final painted panels.

I have posted here about LS before, the LS will be a 100% cover and protection in all the metal joints, welds, hidden sections as long as you apply it properly following the instructions. After you have completed all the repairs and there is zero rust, then first you have to apply primer to all the metal surfaces to seal the metal. Then you proceed to apply the 2 LS products, 1st the sound control and 2nd the LS. 

If you want a smooth finish on the fire wall facing the engine, I can give the process to achieve this result and I can send you pics of our B model cabin when we applied the 2 LS products.

Then you will not require any other applications for sound and heat and metal protection, only your painting products for the external metal panels that you see. And you do the 2 internals of the doors, especially the bottom sills which rust easily. 

Have a look at the LS web page for more information and videos. Good luck.

G'day Harry,

I sure remember your detailed explanations on LS products and your impressions of the results achieved and kept the info on my mind for a while. But finally, or at least for this task I had to decline that option. Main reason is I have no possibility to import liquid stuff. Or better to say I can't order it shipped since avia suppliers don't bring liquids to here. Sure many local body repair material dealers import chemistry by trucks or sea conteiners but they work with big quantities. And nobody seemed here to deal with LS so far. I could also import liquid stuff in a car if travel from Europe but I didn't do much travels of that kind recently. Also it's important to be able to order additional amount of material you apply on a project in a case of such need. So that would be an additional trouble.

Another reason I prefere to use materials I have practice and experience with. So for that cab I made a different choice. We used thick layer of liquid poliurethane sealer which was sprayed on the cowl and the floor on the both sides. Perfect for water access preventing and also very good for sound deadening. I have not much of idea on the temp protection properties but it's not really hot in Russia and I don't plan to drive the truck in a winter too.

[Vladislav]

A bit more to post.

Welded old holes in the LH cowl panel where some poor aftermarket AM/FM antenna was attached and drilled new holes for a stock antenna I purchased from Watts.

[Vladislav]

Discovered new to me rust areas. There's a kind of a stake or a channel along the front of the door openings where you fit door hinges to. R-model cab has them welded of multiple stamped elements put one overlapping another. Rust grew up in between of some of them in the lower areas, as usual. After critycal observation we resolwed to drill off welds and remove at least outer sheets. Very difficult to drill because of bad access. In the end my guy removed a pair of pieces of steel which were a kind of a skirt. We cut new parts of the same shape, drilled holes to corellate the drillings where the weld spots were and arranged nuts welded at the holes on the new parts. So the door opening stakes were going to be reinforsed back again.

Edited March 15, 2020 by Vladislav

[Vladislav]

Prepaired a lot of parts to blast and paint before the time to put them on the cab. The spline flanges were for my military Mack transmission, just happened to paint them in the same lot.

Edited March 13, 2020 by Vladislav

[Vladislav]

One more part of the story.

Had to hang up the cab in horizontal position to temporary remove the sleeper entrance inserts for blast and paint and kept it hanging for a few days that way since the rear wall was not reinforsed without. When the inserts got paint (they turned out green because they came to the paint shop together with some chassis parts) I cleaned and etch-primed the areas they would be installed. Than applied polyurethane body sealer, put the inserts in place and attached them with pulling rivets installed into the holes drilled earlier. Had to be quick with riveting and wiping the excess of the sealer off because it was becoming set up really fast. The rivets I bought were made of steel not aluminium to be friendly with cab sheet metal. So not easy to work with especially when in rush.

Edited March 15, 2020 by Vladislav

[Vladislav]

When the sealer set up well, the paint guy ready and weather sunny with a bit of freeze I gave the cab one more overall blast and towed the trailer to a paint shop. There a crew of 3 men consisting of me, my helper and my paint buddy spent about two hours removing sand out of all channels working with two vacuum cleaners and air gun. Finally 2 of us went home and when I came back on the next day the cab was covered with a solid layer of self-etching primer. Ufff....

 

Edited March 15, 2020 by Vladislav

[mowerman]

holy shit,,,,i didnt realize you were doing all that,,,,my god  what alotta work,,,,but its looking real good and now you have abrand new cab,,,,,,,,,wow hats off to you,,,i usually never come to this section....bob

[41chevy]

With the work you did the cab is in my opinion better than Mack made.  Paul

[Vladislav]

3 hours ago, 41chevy said:

With the work you did the cab is in my opinion better than Mack made.  Paul

Regarding the materials applied it seems better definitely. But taking that I blasted the most of zink off the steel it's worse.  So I try to keep a balance

[Vladislav]

3 hours ago, mowerman said:

holy shit,,,,i didnt realize you were doing all that,,,,my god  what alotta work,,,,but its looking real good and now you have abrand new cab,,,,,,,,,wow hats off to you,,,i usually never come to this section....bob

These technical forums are not as active on posting as the general discussions or odds and ends but contein interesting subjects from time to time. So worth checking out once in a week or two. Thank you for the comment.