Building a roof rack deck on a GMT800 Suburban Z-71

[rayra]

man, 500 views since I made the recent updates of the build and no comments. I'm wondering why? Is it too strange a thing? Nobody build anything anymore, can't relate? No suggestions for improvements, or constructive criticisms? part of posting stuff here is to share ideas, techniques, experience.


As for the project itself -

I keep looking out the window at my roof deck. After three days the paint finish is quite hard and not tacky as I feared in this blistering heat. And I note that I'm getting some differential bowing in the two panels. Saw a bit of that at the initial install. Regrettably I cut the two panels out of two different sheets of plywood (working a couple projects at the same time), so the stresses are different. And worse, I made no effort to match the natural curve before cutting the shapes. I fear one is naturally cupping downward, the other upward.
I ventured out in the heat yesterday to get some aluminum 3/4" C-channel. I cut some 6" long clips to bridge the seam of the two panels at each end, forcing them into alignment. I still need loosen the crossbrace nuts at front and rear and depress the ends of the panels, inducing both to curve the same way and locking them down. And paint the C-channel bits to match. But it's too damned hot right now. Did just enough to get the clips on and forestall any more warping. At some point in time the decks will basically take and hold that position. Not long in the beating sun of summer.

1100

 

[RadarVector]

Awesome!


Sent from my iPhone using Tapatalk

 

[jgaz]

Nice job. If it doesn't work out long term it sure won't be because you didn't put in the necessary thought or effort in the design and construction.
Slightly off topic but I just saw your center console build via a link in another thread. You show some serious woodworking skills in that build!

 

[Rezarf <><]

Nice job, you could also spend a Saturday, drop the headliner and add some Reflectix to the roof, it'll cut a significant amount of heat. Cutting a few shades for the rear windows in our Land Cruiser allowed us to run the AC two notches lower than usual in the same temps. I was astounded they made that much of a difference but you are eliminating some huge passive solar heating panels by blocking some of the windows. I'm a believer.

 

[rayra]

Thanks, and yes, more efforts to curtail solar insolation to come. I'll have the headliner down in the future for some other projects - anchor points for a cargo barrier net, mounting locations for a couple ceiling racks for fishing poles and radio antennae, and running wiring into the roof rack footings for rooftop solar power connections and rear flood lights mounted in the rear housings of the roof rack. I'm looking at the lightweight mylar radiant barrier material used in attic insulation, added to the headliner, between headliner and roof skin.
I'm also considering clear window e-film for IR / UV reduction.

I've been doing most of the inexpensive stuff, stuff I can build myself, first. Then I'll work on the more expensive products that I have to buy. Inverters, solar charge controllers, solar film, more batteries, some LED lighting, off-road shocks / suspension lift. And then a customized grill guard / brush guard / skid plates. I intend to do much of the welding for those, but my welding skills are 20yrs rusty right now.

 

[Burb One]

Thanks, and yes, more efforts to curtail solar insolation to come. I'll have the headliner down in the future for some other projects - anchor points for a cargo barrier net, mounting locations for a couple ceiling racks for fishing poles and radio antennae, and running wiring into the roof rack footings for rooftop solar power connections and rear flood lights mounted in the rear housings of the roof rack. I'm looking at the lightweight mylar radiant barrier material used in attic insulation, added to the headliner, between headliner and roof skin.
I'm also considering clear window e-film for IR / UV reduction.

I've been doing most of the inexpensive stuff, stuff I can build myself, first. Then I'll work on the more expensive products that I have to buy. Inverters, solar charge controllers, solar film, more batteries, some LED lighting, off-road shocks / suspension lift. And then a customized grill guard / brush guard / skid plates. I intend to do much of the welding for those, but my welding skills are 20yrs rusty right now.

Everything looks great! I'm interested about this roof insulation, I was under the impression, most of the heat cam from UV through the windows, and that the headliner provided a decent amount of insulation. If you end up doing that, definitely post it!

 

[rayra]

I will. I was poking around the headliner a bit when I re-upholstered the sun shade and was messing with removing a fold down TV screen in the 2nd row and the headliner itself is a fibrous sort of pressboard, less than a 1/4" thick with no visible insulation around the forward / sunroof area. Don't know about the rear area yet.

And yes, with all that glass, it is the bigger issue. Damned Suburbans are a greenhouse on wheels. I'm definitely looking at clear e-film application.

My large GSD just had an unfortunate bowel accident on the way home from the groomers on Tuesday, everything is stripped out of the rear of the vehicle (again) right now, this evening I'm putting a bunch of 'dynamat' type material on the rear floor, under the rag insulation and the 2nd row floor area. Except the future fuel pump surgery location.

The mylar stuff I'm referring to -

It's sort of like a mylar-coated bubble wrap. It weighs less than an ounce per square foot and is fairly thin in cross section. My expectation / plan is that I can drop the headliner panels and just coat their top sides with a layer of this stuff. Maybe even two layers. A light application of spray glue just to keep it in place when re-installing things. I'm not sure if it's directional, but my biggest concern is keeping heat out, not holding it in.

Like a mylar emergency blanket, it works as a radiant barrier and doesn't work well in contact. So I'll put it on the headliner not the metal roof skin itself. If I can put two layers on without it being squeezed against the roof skin, I'll do so.

I'll probably do a topic in General Mods when I do, and re-cap the butyl rubber stuff in that topic too.


48" x 25' roll is $46 at Home Depot - http://www.homedepot.com/p/Reflectix-48-in-x-25-ft-Double-Reflective-Insulation-BP48025/100052556

Maybe if I can show some benefit of it I can sucker er I mean provide an economic opportunity to others and sell off the bulk of the roll. Only need about 8' of it.
Come to think of it, scratch that. If it works it's a double layer and I'll put the rest in the wife's Tahoe

 

[boll_rig]

You did it! And I have to say it is very sleek looking, hardly noticeable at all from a standing level I presume. Curious to see how long that paint lasts or I suppose how long the wood lasts. If you lived in oregon I would have said definitely use epoxy, but I think youll be okay for a long time in the desert.

Love the idea of it being a backboard as well, great mod. Only thing i could possible say for MK2 would be to make it standable and to be able to put a lawn chair up there for sunsets (way too hot for mid day and no shade)

Keep us posted on the insulation, I have been seriously wondering about use that mylar bubble wrap stuff under my half inch foam insulation of my pop top roof.

Nice work Rayra!

 

[rayra]

hey thanks very much. I'm like a glacier. I'm slow as hell but I get there eventually.


Here's some pix of the 'dynamat' install. It's about twice as thick as the butyl rubber window flashing stuff. But costs about 10x as much. Only other difference I can see is the silvered plastic layer on it. Not sure if it's metallic. I got about 40sq' for free, wo while I had the rear apart again I went ahead and took things further apart and laid it down everywhere but where the floor will be cut for the fuel pump replacement.

It's kind of heavy, boll_rig, not sure it's a good idea for your pop-top. I think you'd do better there with the mylar bubble wrap sort of stuff. An air gap product. This rubber stuff is more about noise control.

I'll do the ceiling insulation thing some time this summer and post a separate topic on it, and re-post some of this peel and stick stuff there too.

 

[Burb One]

hey thanks very much. I'm like a glacier. I'm slow as hell but I get there eventually.


Here's some pix of the 'dynamat' install. It's about twice as thick as the butyl rubber window flashing stuff. But costs about 10x as much. Only other difference I can see is the silvered plastic layer on it. Not sure if it's metallic. I got about 40sq' for free, wo while I had the rear apart again I went ahead and took things further apart and laid it down everywhere but where the floor will be cut for the fuel pump replacement.

It's kind of heavy, boll_rig, not sure it's a good idea for your pop-top. I think you'd do better there with the mylar bubble wrap sort of stuff. An air gap product. This rubber stuff is more about noise control.

I'll do the ceiling insulation thing some time this summer and post a separate topic on it, and re-post some of this peel and stick stuff there too.

When you do the floor cut, could you take measurements/ pictures? I've been putting that off for awhile now, maybe it will push me to do mine as well

 

[rayra]

This guy totally lays it out.

https://www.youtube.com/watch?v=Ho2pk8okztE

 

[Burb One]

This guy totally lays it out.

https://www.youtube.com/watch?v=Ho2pk8okztE

Awesome, thanks!

 

[rayra]

Road test report, mixed results mostly good.
Today I drove down into L.A. proper (to see the Space Shuttle Endeavour) and along the way got some good high speeds on the freeway.
Great news - the roof deck is still attached to the vehicle.
The Good News, no noticeable noise below 65MPH and about about 72mph.
The No-so-good news, between 65-72 there's a discernible moan. By ear and presumption I'd say it comes from venturi formed by the close fit of the forward cross brace and the deck.
The better news, putting the sunroof in the up position seems to shift the airflow enough to greatly decrease the moan in that speed range. And what is left is lost in the wind-buffet noise of the open sunroof itself or by opening the windows any degree at all.


in related news, the additional sound matting wiped out ALL road and tire noise from behind the driver seats. Dead as a tomb back there. Wish I'd put some in the forward footwell / front wheel-well area. I can do a double- or triple-layer of window flashing there cheaply enough and will do that very soon. My Yokohama tires do hum a bit.

 

[rayra]

two high speed trips of ~80mi, holding up well. And it certainly seems to be aiding with total heat and ease of cooling the vehicle interior.
But the drone moan has got to go. I'll be making a couple changes re that in about two weeks, have some othe rstuff I have to do first.

 

[Buddha.]

I like rack deck idea. I was thinking about doing something like that when I did my road trip last month.