After yesterdays downer…. sorry but how can you appreciate what you have if you don’t see what could be…… there are so many factors throughout the GMC that effects other things is important to think through all you attempt.
As a little of the information section of todays pile, here’s one that man you can get yourself in a big mess with!
Water leaks… Oh yeah, lets wade into this cesspool! Lets take the case of that guy we all had to put up with for a while that said after having his coach leak tested and sealed it started leaking again which he felt soo grievous he made some waves. Listen, the GMC body is unlike anything else on the road and that’s not said because of pride or whatever….. It is an aircraft …expendable joint body just like an aircraft. If an airplane was a rigid structure it would break up in flight…. a plane has to expand, contract and give to achieve a reliable structure……. that’s also how a GMC was made and does that.
The “ladder” frame construction is like a boat trailer, take the boat off and it’s a flimsy platform strong enough to carry the boat but still….. the drive train is a “tug motor”, a gas powered heavy torque pair of wheels that can pull most anything…and then plop an aircraft fuselage on that and you have a GMC Motorhome. hit a big pothole, take a wild ride down a dirt road or even go offroad like many do and expect water leaks. It was designed as a superior highway cruiser not an off road escape machine!
The designers understood this and even created a “seal system” for the roof to body seam running front to back. It’s conceivable from front to back for that seal to flex 1/4″ and more! and if they made any of these pressure joints solid it would effect the rest of the flexible body.
OK so under that rail sporting the rain gutter (not on some 73’s) there is high elastomer rate sealant under that rail… the rain is attached to the middle of the floating system which ill allow it to pivot at the middle and allow the plates to flex as they need to.
This “system” or any seal system needs periodic servicing to renew it’s sealing qualities. That original sealant … the best they could come up with at the time…. was a roll of butyl tape. Each screw if leak will funnel water to a hollow front to rear extrusion which will allow the water to drop anywhere there is a penetration in thay opening and most certainly just in front of the rear speakers or just behind the driver/passenger seats.
This seal system should have been serviced somewhere around 1989…… has yours been resealed? There are so many really awesome sealants available today………so where is this story going?
This is not a tangent.. a customer some 15 years ago was a sailor and believed (S-5200 quick cure) would hold anything… and he was right……. For those of you who don’t know….boat hulls are glued together with this tune dip….. the stuff just will not let go but that creates a problem when you glue these rail and it’s ealing system down with S-5200.
For sure it dries harder than woodpecker lips but there are 2 qualities needed in the sealing method that rail needs. There is sealing and then there is adhesion…….. we need sealing qualities in a serviceable seal not adhesion……. that would not allow the seal to come apart…..ever! S-5200 is not as much a sealer as it is an adhesive… you achieve a seal with this stuff through sheer mass of material. Oh and taking that leaking rail off because he didn’t lay down a continuous bead of the stuff leaked really bad…. getting that rail off was not pretty! A new rail had to be used which means a motorhome had to go down because every coach needs 2 of these unique covers for the sealing system.
Now sure you could try some other way to allow a corner joint to stay flexible. You could say “we don’t need no flexible joint” and glue that puppy down! Thin other joints would be effected and the (airplane flying with stiff wings falls from the sky)! You really should not do that……. this body has unique stresses no other vehicle has, it needs to be approached from that aspect…. all previous ideas of how to put back together a car will not work on your GMC.
So the story here…….. research and know what you’re doing on this body….. what a fantastic body guy wants to do may destroy your coach… or at least make things not right…..
So why do 1973 and many 74 model GMC’s have rivets scattered over the body sometimes? UAW workers and the epoxy bonding technology were not on the same page. Never bonding a body together like an aircraft……. seams were popping before the coaches were finished……. Techknology increased and Bubba figured out how to glue stuff together and this one of a kind body started holding together better. Don’t be scared if you see rivets… it’s solid, just has a few extra beauty marks!
The takaway on this should be know how to treat each of the seam types on your coach…. know the characteristics of the sealant you are getting ready to use, apply the right stuff properly and always be vigilant not to hit potholes, twist the body in a swail or drive fast enough on a dirt road to not feel it……. you guys with Jeeps know what I mean!
Hey and if that you and you don’t intend on ever stopping fine……. go over the coach often and stay up with the leaks.
Cool machine hey? That’s what drew me to the GMC. I was into fat fender Mopar… met a GMC Motorhome and the love affair had to happen. Why spend big dollars to put together a cool car then sit at a car show in a sagging lawn chair hoping no one scratcher your car and the only fun is saying over and over what the car was and some silly story before they walk off………. what’s good about that! If you have a really nice antique car go drive the wheels off……… I can put the same money in a GMC Motorhome… have the same pride and when the party is over I can take a shower, cook dinner and sleep in my baby…….. sweet dreams in that T bucket!
These really are unique machines and I think you made a smart investment in getting one. You can never be homeless owning a GMC!
See ya tomorrow… I had a whole mornings pics planned to show off…. but I just sucked up the attention span…… Oh here’s a new project we’re bringing in 
This Avion camper has really withstood the test of time…… has it’s own charm and style.. I like the blackout accents. With a new black cover AV, new MaxVent black vents and some other stuff this will be a cool set-up. A doctors getaway machine…….. a worthy subject……… of course GMC’s are everywhere around here 
Well that’s a cool Revcon there too butit’s wild around here. Got the motor back together on the blue truck 
The keeper grooves in the valve stems were worn out……… hey nice rebuild hey…… sealant dried overnight it should fire today 
What the heck, I’ve already blown my morning…. the guys just got here and showed me something that’s really cool. lemme process these pics… I’ll be back…..
For you guys not having to go to work…. glad to see u back….. The guys were right, this is kinda cool……. so I’ve been showing you the restoration on this 1978 F250 longbed Ford truck 
As bone stock as you will see… not a points concourse …… not your nowman “driver”, it’s a concourse job made to drive. Some of you may also know we have another Ford pickup under restoration here……. it’s a 1979…. shortbed and the direction is NOW! Not 5′ tall tires and stuff hanging from the trailer hitch but a sharp truck! So check out this new hood set up on this truck. 
Now, just like any hood it will lif to check oil, water or whatever 
Now this is a kit.. we didn’t design this but incorporated it into this restoration. The hood will also do this 
Talk about access 
This same 351 Industrial motor has FiTech fuel injection, the same in dash AC and billet pulley system. Bot are sporting fan boxes because of the AC….
Jared has the guys organized and working (that’s Jared in the above pics) so I think I’ll come back here and say a few more things…….. All the time I was wasting spending time elsewhere has given me more time to focus here. Hey, if it’s boring or the kids need to get to school… heaven forbig the boss call……. you gotta go or tired of seeing fun stuff, we’ll see ya later and thanks for the visit…….
If you can pour another cup of coffee, I’ll be back after processing a few more pics….. see ya then……
Are we on for Page 2? Well alrighty then………
These 2 Ford trucks are a “yen/yang” as far a quality restoration goes…… we pulled out gobbs of bondo in these projects (loos were VERY deceiving) 
the roof on the shortbed was replaced because of the rust 
Both dashes are awesome in their own way
Yes, Mac at custom instrument panels crafted us a custom dash cluster….
There was a guy on Facebook who commented if our business plan is not bringing in business I should change from within……… of the surface that may sound like a crass thing to say but he is right on…… and BTW that’s happening. The GMC Motorhome is my passion and we will always do our best and along with that so many are starving for good , work. “A good deal is a fair deal and we have no shortage of folks who understand that.
Thanks to all of you who support us and I promise to keep doing what we are not going to change …. no matter how cutthroat others seem to be. Thanks for the visit and your support……. .
It would be a very very rare aircraft to have expandable joints. The only ones that come to mind is a SR-71 and Concord. SR-71 and Concord needed it because of the extreme range of skin temperature they operated in due to friction heating at high mach numbers. And I think the Concord it was just the cabin floor that floated not skin joints on the outside. Walking around the AIrbus I fly I see no flexible joints all solidly riveted together.