Is this a good idea ? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**Bernie** · 02-03-2003, 10:17 AM

I was replacing cab corners and rockers. Nothing that I can do can completely seal the rockers so at some point water is going to get in there and start to rust them. There is that urethane foam in an aerosol can . I use it to seal and insulate around windows in my house. You squirt it in and it expands to fill voids. Has anyone thought about filling the space behind the rockers and the cab supports with it ?

**CPNE** · 02-03-2003, 10:30 AM

I believe that would do more harm than good by trapping moisture.

JimKshortstep4x4 · 02-03-2003, 10:31 AM

We spray the inner parts with a thinned tar mixture to seal the seams and cover the surfaces. (Home made undercoat).

Jim

Truckstr · 02-03-2003, 10:46 AM

DO NOT use spray-in insulating foam.

You'll be sorry - if you do. It'll trap moisture and actually promote rusting.

Personally, I like treat the bare metal with Metal Prep and then spray an undercoating in to seal it as best I can. That said, Eastwood offers some pretty good spray in coatings - some that would seem to be well suited for this purpose.

Good Luck!
Jeff

HIGH724X4 · 02-03-2003, 11:49 AM

Insulated Foam !! (##?/>*!!)

Let me Find My pics of the problem from the previous owner.
Probably kept him warm, but, created a giant sponge and no metal anymore. He INSULATED the cab supports, rockers (fully) and the cab corners, what a mess. I would not do that, unless, you plan on using it as a farm truck, but I think it might be harmful to the animals, SO I guess, it ain't worth Sh$$..
Just my .02$ (Bad Experience)

yellowgmc · 02-03-2003, 12:36 PM

spray in foam sucks!!!!! there's no point in replacing all that metal, it'll rust out real quick. check the lower right hand corner of this pic. the foam was sprayed in from the inside.

**John Fabris** · 02-03-2003, 12:52 PM

A better option is to weld more sheetmetal in the bottom to close up the cab, and then put in a hole and a rubber plug (like what you see on most car floorboards. that way it is closed up (no more noise) and you still have the ability to open it up to air out.

Longhorn Man · 02-04-2003, 12:28 AM

You could coat the inside of the metal with POR 15.

**Bernie** · 02-04-2003, 10:35 AM

Sooooo, I guess it's not a good idea. Thanks to all.

02-03-2003, 10:17 AM	#1
Bernie Senior Member Join Date: Jan 2001 Location: Northern Illinois Posts: 516	Is this a good idea ? I was replacing cab corners and rockers. Nothing that I can do can completely seal the rockers so at some point water is going to get in there and start to rust them. There is that urethane foam in an aerosol can . I use it to seal and insulate around windows in my house. You squirt it in and it expands to fill voids. Has anyone thought about filling the space behind the rockers and the cab supports with it ? __________________ Bernie

02-03-2003, 10:30 AM	#2
CPNE Resident Curmudgeon Join Date: Dec 1999 Location: NH Posts: 6,664	I believe that would do more harm than good by trapping moisture. __________________ Currently on or near the homestead: 67 Chevy SWB 2WD stepside 350/3 on tree (Pat's) 67 GMC SWB 2WD Fleet 402/auto (Brian's under construction) 67 Chevy 3/4 ton 2WD 402/auto (Business Hauler) 67 Chevy 1 ton dually 2WD 396/4 speed (Former business hauler, Needs TLC) 68 Chevy 1/2 ton Suburban 2WD 250 six/3 on tree (Brian's Needs TLC) 70 Chevy 3/4 ton 4WD 350/4 speed (Pat's - Disguised as a 68 GMC) 71 Chevy SWB stepside (Crushed by tree - parts donor) 72 Chevy 3/4 ton 4WD (Parts donor) 72 Chevy 3/4 ton 4WD Suburban (Parts Donor) 72 GMC 3/4 ton 4WD 292 six/4 speed (Mine - Disguised as a 67 GMC) 81 GMC 4WD Dually Dump Body 350/4 speed (Business Hauler) 82 Camaro Z/28 355/Super T-10 (Pat's toy) 93 Caprice 9C1 (Brian's Cop Car) 02 Toyota Camry (Reliable but a souless steel and plastic hulk) 2011 2SS RS Camaro M6 Factory Hurst Shifter Maybe I need to sell some of this crap Yet another Bozo with a sawz-all

02-03-2003, 10:46 AM	#4
Truckstr Registered User Join Date: Nov 2002 Location: Lebanon, Tennessee Posts: 1,372	DO NOT use spray-in insulating foam. You'll be sorry - if you do. It'll trap moisture and actually promote rusting. Personally, I like treat the bare metal with Metal Prep and then spray an undercoating in to seal it as best I can. That said, Eastwood offers some pretty good spray in coatings - some that would seem to be well suited for this purpose. Good Luck! Jeff __________________ Jeff '67 short Fleet; my ongoing project. '66 long Fleet; my original "baby." Live life or bust trying.

02-03-2003, 11:49 AM	#5
HIGH724X4 Registered User Join Date: Nov 2000 Location: LAWRENCEBURG, INDIANA Posts: 298	Insulated Foam !! (##?/>*!!) Let me Find My pics of the problem from the previous owner. Probably kept him warm, but, created a giant sponge and no metal anymore. He INSULATED the cab supports, rockers (fully) and the cab corners, what a mess. I would not do that, unless, you plan on using it as a farm truck, but I think it might be harmful to the animals, SO I guess, it ain't worth Sh$$.. Just my .02$ (Bad Experience) __________________ 72 CHEVY FLEETSIDE 4X4 K10 (SOLD TO JAMIE72, BUT BLAZER GAL PULLED AWAY WITH IT LOL!!!) Will Own one Again!!! 1967 CAMARO (PRO-TOURING PROJECT) Lawrenceburg, Indiana.. AOL IM: kbillcad

02-03-2003, 12:36 PM	#6
yellowgmc Getting cabin fever?!?!?! Join Date: Oct 2002 Location: chisholm, mn Posts: 1,679	spray in foam sucks!!!!! there's no point in replacing all that metal, it'll rust out real quick. check the lower right hand corner of this pic. the foam was sprayed in from the inside. Attached Images __________________ Member of the Discs Up Front Club 1972 GMC 1500 1994 F-150 XL 4x4 Tact is for people not whitty enough to be sarcastic

02-03-2003, 10:31 AM	#3
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	We spray the inner parts with a thinned tar mixture to seal the seams and cover the surfaces. (Home made undercoat). Jim

02-03-2003, 12:52 PM	#7
John Fabris TOTY 2006 Join Date: Dec 1999 Location: Magalia CA USA Posts: 2,270	A better option is to weld more sheetmetal in the bottom to close up the cab, and then put in a hole and a rubber plug (like what you see on most car floorboards. that way it is closed up (no more noise) and you still have the ability to open it up to air out. __________________ John Fabris 67 C10 SWB

02-04-2003, 12:28 AM	#8
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	You could coat the inside of the metal with POR 15.

02-04-2003, 10:35 AM	#9
Bernie Senior Member Join Date: Jan 2001 Location: Northern Illinois Posts: 516	Sooooo, I guess it's not a good idea. Thanks to all. __________________ Bernie

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