cowl area cancer - The 1947 - Present Chevrolet & GMC Truck Message Board Network

chevyforever · 11-01-2002, 11:30 PM

has anyone ever had the fun experience of getting a classic chevy with absolutely no cancer in the rocker panels or cab corners, yet to find out with further inspection that the cowl area of the truck has pretty bad cancer problems? it sux bad. i found that my cab has cancer on each side of the truck where the cowl meets the side of the truck, and particularly bad where the radio antennae wire comes out of the cab. i was wonderin if it is at all posible to repair this sheetmetal. i would cut out the bad and weld in all new sheetmetal, but i dunno if that would be an accurate fix or not.

any help is greatly appreciated! chevyforever

**ThreeQuarter** · 11-01-2002, 11:50 PM

TREES KILL COWLS!

I feel for you man. My old friend has recently discovered a bad case of cowl rot in his '68. I tried a couple of times to fix it without welding, but to no avail. I am curious now if it can be done with patches, instead of replacing the whole cab. Good luck and I'll be looking for a response.

chevyforever · 11-01-2002, 11:58 PM

thanks for your response.
i was wondering the same also, if i could just weld in some home-made patches, since non are factory made to repair it. it wouldn't bother me any because i have much experience with welding sheetmetal, but what i am worried about is when i get the rot fixed, what i can do to ensure no more rot will happen,(other than not parking under trees)!!

bobs409 · 11-02-2002, 09:21 AM

You have to stop leaves from getting in there. I hot glued fiberglass screen to the underside of the cowl on mine (yeh, I know that sounds kind-a-redneck but it works) From the top, it looks great and does the job. Liked it so much, I did my other truck too.

imaindianoutlaw · 11-02-2002, 10:47 AM

I have the same problem but am planning on getting another cab! I think its the only way out!

tom hand · 11-02-2002, 11:00 AM

I have seen some pretty rust free trucks that have cowl rot from wet leaves staying in there. And it rusts from the inside out, so really won't know how bad your "new" cab is. Unless it is really bad I would break out the die grinder and mig welder and fix it.

hanssolo · 11-02-2002, 11:44 AM

Thats part of the reason the guy I bought the truck from replaced the '69 cab with a '72. I sprayed the cowl and entire firewall with rubberized undercoating. I figure besides moisture protection it helps with some noise control also. Some guys don't like to do that to a firewall but its not an open -hood showtruck. Its better than a rusted out firewall. I also glued screen under the cowl openings.

imaindianoutlaw · 11-02-2002, 06:50 PM

My truck has rust on the fire wall where it meets the cowl and the cowl leaks into the truck on both sides in the cab where it is seamed on the bottom!

The rest of the truck is awsome!

chevyforever · 11-02-2002, 11:31 PM

thanks for all the info and tips.
i got to looking at it today, and it doesn't seem too impossible to repair it by cutting out the rotted and welding in new sheetmetal, i will just take my time to do it right. i think that i am going to use that spray on undercoating inside and out of the firewall/cowl area to keep moisture out, and to also deaden a little sound. also, i was looking around the farm today and found a roll of what looks like the screen used in windows on a house, so i'm gonna use some of that to keep the leaves out.

thanks for the help

bobs409 · 11-03-2002, 08:59 AM

Be sure to use the fiberglass screen. If you use metal type it will probably rust away eventually.

Just my opinion but I wouldn't undercoat the outside of the firewall. That could be painted body color or black and hold up better than undercoat. Would look much better too.

Just my .02 cents worth.

chevyforever · 11-03-2002, 10:53 PM

where can i get the fiberglass screen? is it just the fiberglass sheets you use when doing any fiberglass work?

thanks for the tips.

Retlaw · 11-03-2002, 11:28 PM

I found stainless steel screen at a local hardware store. I plan to use it to do the cowl on my Sub.

bobs409 · 11-04-2002, 09:08 AM

You can get this at any home supply place like Lowes, Home Depot, etc.

It's just fiberglass replacement window screen used on storm doors and window screens.

MOTHERTRUCKERS · 11-04-2002, 10:36 AM

If interested I have some unrusted cowl and firewall pieces for patching in cabs.

chevyforever · 11-05-2002, 11:45 PM

thanks tons to everyone who answered my quest for help!
i will be repairing the rust and getting ahold of some fiberglass screen to save my a$$ the next time around.

forever

Paul Clark · 11-06-2002, 12:05 AM

Sounds kinda simplistic - but
What, and where the "what" was, made it rust?
Eliminate the cause and the rust stays away. - At least until next winter.

Uncoated metal?
Sand and paint it.
Leaves from trees (good source, huh)?
Cut down the tree, or park someplace else.
Plugged drainage holes?
Don't think there are any in the cowl, but something is happening to trap moisture in there.
Find that, and with a little paint, you're good to go.

28buick · 11-06-2002, 08:37 AM

I recently had the same problems with my 72 Blazer only worse. If you have rot by the antena you should think about removing the windshield because water pockets beneath the gasket. All these areas can be repaired if you have the time. Its also much easier if you take the fenders off because the rot tends to creep behind the fenders. I had to replace the entire windshield frame on my truck due to perpetual leaking of the top. For sealing the cowl I used anodized aluminum screen from the hardware store. It works great. Just screw it to the cab with the cowl and windshield wiper screws.

11-01-2002, 11:30 PM	#1
chevyforever Some like em' long! Join Date: Nov 2002 Location: Grace, Idaho Posts: 69	cowl area cancer has anyone ever had the fun experience of getting a classic chevy with absolutely no cancer in the rocker panels or cab corners, yet to find out with further inspection that the cowl area of the truck has pretty bad cancer problems? it sux bad. i found that my cab has cancer on each side of the truck where the cowl meets the side of the truck, and particularly bad where the radio antennae wire comes out of the cab. i was wonderin if it is at all posible to repair this sheetmetal. i would cut out the bad and weld in all new sheetmetal, but i dunno if that would be an accurate fix or not. any help is greatly appreciated! chevyforever __________________ 1971 chevy c10 lwb- 300 hp 350 crate motor, soon to be more with ported and polished 62cc chamber 461 double humps, TH400, 3.73 posi, used to be my uncle's truck 1972 chevy k10 lwb- 350,4 spd, old and tired, dad bought brand new and is now mine 1968 chevy c20 lwb- 327, 4 spd, was originally a 50th anniversary truck 1990 GMC K1500-just my runaround truck 1982 Chevy K10 shortbed, new motor and new paint, another project in the mix of the others. IMPORTS SUCK!

11-01-2002, 11:50 PM	#2
ThreeQuarter Senior Member Join Date: Jun 2000 Location: Texan in Iowa Posts: 2,522	TREES KILL COWLS! I feel for you man. My old friend has recently discovered a bad case of cowl rot in his '68. I tried a couple of times to fix it without welding, but to no avail. I am curious now if it can be done with patches, instead of replacing the whole cab. Good luck and I'll be looking for a response. __________________ Ben '68 Chevy C10 Custom LWB 327/TH400 2nd owner '16 GMC Sierra 1500 SLE Dblcab 4wd 5.3

11-01-2002, 11:58 PM	#3
chevyforever Some like em' long! Join Date: Nov 2002 Location: Grace, Idaho Posts: 69	trees suck! thanks for your response. i was wondering the same also, if i could just weld in some home-made patches, since non are factory made to repair it. it wouldn't bother me any because i have much experience with welding sheetmetal, but what i am worried about is when i get the rot fixed, what i can do to ensure no more rot will happen,(other than not parking under trees)!! __________________ 1971 chevy c10 lwb- 300 hp 350 crate motor, soon to be more with ported and polished 62cc chamber 461 double humps, TH400, 3.73 posi, used to be my uncle's truck 1972 chevy k10 lwb- 350,4 spd, old and tired, dad bought brand new and is now mine 1968 chevy c20 lwb- 327, 4 spd, was originally a 50th anniversary truck 1990 GMC K1500-just my runaround truck 1982 Chevy K10 shortbed, new motor and new paint, another project in the mix of the others. IMPORTS SUCK!

11-02-2002, 09:21 AM	#4
bobs409 1969 Custom 30 wrecker Join Date: Sep 2001 Location: Pottsville, Pa Posts: 2,611	You have to stop leaves from getting in there. I hot glued fiberglass screen to the underside of the cowl on mine (yeh, I know that sounds kind-a-redneck but it works) From the top, it looks great and does the job. Liked it so much, I did my other truck too. __________________ Bob 63 Impala 283/PG/3.36 (under restoration) 66 Impala 327/PG/3.36 66 Chevelle SS 409/M22/3.55 69 Chevelle 307/PG/3.08 (future restoration) 69 C10 short stepside 454/TH350/3.73 69 Custom 30 tow truck 350/4 spd/4.10 (resto done, CRUISIN TIME!) 71 Cheyenne 20 fleetside 350/4 spd/4.10 71 Chevelle 6/PG/3.08 72 Chevelle 454/M21/4.10

11-02-2002, 10:47 AM	#5
imaindianoutlaw GMC SHORT FLEET F/S Join Date: Jun 2000 Location: SOUTH WILLIAMSPORT PENNSYLVANNIA Posts: 2,117	I have the same problem but am planning on getting another cab! I think its the only way out! __________________ CHARLES WADE HEIN HVACR FOREMAN. LEWISBURG U.S.P.

11-02-2002, 11:00 AM	#6
tom hand CCRider Join Date: Feb 2000 Location: Olive Branch,MS,USA Posts: 2,232	I have seen some pretty rust free trucks that have cowl rot from wet leaves staying in there. And it rusts from the inside out, so really won't know how bad your "new" cab is. Unless it is really bad I would break out the die grinder and mig welder and fix it. __________________ 72 GMC Sierra SWB almost finished---- 84 Softail Olive Branch MS

11-02-2002, 11:44 AM	#7
hanssolo Registered User Join Date: Sep 2001 Location: central Ill. USA Posts: 447	Thats part of the reason the guy I bought the truck from replaced the '69 cab with a '72. I sprayed the cowl and entire firewall with rubberized undercoating. I figure besides moisture protection it helps with some noise control also. Some guys don't like to do that to a firewall but its not an open -hood showtruck. Its better than a rusted out firewall. I also glued screen under the cowl openings. __________________ 69 C10 longbed: 357c.i. /TH400/3.73s/AC/ beige primer/saving $ for paint ______________________________

11-02-2002, 06:50 PM	#8
imaindianoutlaw GMC SHORT FLEET F/S Join Date: Jun 2000 Location: SOUTH WILLIAMSPORT PENNSYLVANNIA Posts: 2,117	My truck has rust on the fire wall where it meets the cowl and the cowl leaks into the truck on both sides in the cab where it is seamed on the bottom! The rest of the truck is awsome! __________________ CHARLES WADE HEIN HVACR FOREMAN. LEWISBURG U.S.P.

11-02-2002, 11:31 PM	#9
chevyforever Some like em' long! Join Date: Nov 2002 Location: Grace, Idaho Posts: 69	thanks for all the info and tips. i got to looking at it today, and it doesn't seem too impossible to repair it by cutting out the rotted and welding in new sheetmetal, i will just take my time to do it right. i think that i am going to use that spray on undercoating inside and out of the firewall/cowl area to keep moisture out, and to also deaden a little sound. also, i was looking around the farm today and found a roll of what looks like the screen used in windows on a house, so i'm gonna use some of that to keep the leaves out. thanks for the help __________________ 1971 chevy c10 lwb- 300 hp 350 crate motor, soon to be more with ported and polished 62cc chamber 461 double humps, TH400, 3.73 posi, used to be my uncle's truck 1972 chevy k10 lwb- 350,4 spd, old and tired, dad bought brand new and is now mine 1968 chevy c20 lwb- 327, 4 spd, was originally a 50th anniversary truck 1990 GMC K1500-just my runaround truck 1982 Chevy K10 shortbed, new motor and new paint, another project in the mix of the others. IMPORTS SUCK!

11-03-2002, 08:59 AM	#10
bobs409 1969 Custom 30 wrecker Join Date: Sep 2001 Location: Pottsville, Pa Posts: 2,611	Be sure to use the fiberglass screen. If you use metal type it will probably rust away eventually. Just my opinion but I wouldn't undercoat the outside of the firewall. That could be painted body color or black and hold up better than undercoat. Would look much better too. Just my .02 cents worth. __________________ Bob 63 Impala 283/PG/3.36 (under restoration) 66 Impala 327/PG/3.36 66 Chevelle SS 409/M22/3.55 69 Chevelle 307/PG/3.08 (future restoration) 69 C10 short stepside 454/TH350/3.73 69 Custom 30 tow truck 350/4 spd/4.10 (resto done, CRUISIN TIME!) 71 Cheyenne 20 fleetside 350/4 spd/4.10 71 Chevelle 6/PG/3.08 72 Chevelle 454/M21/4.10

11-03-2002, 10:53 PM	#11
chevyforever Some like em' long! Join Date: Nov 2002 Location: Grace, Idaho Posts: 69	where can i get the fiberglass screen? is it just the fiberglass sheets you use when doing any fiberglass work? thanks for the tips. __________________ 1971 chevy c10 lwb- 300 hp 350 crate motor, soon to be more with ported and polished 62cc chamber 461 double humps, TH400, 3.73 posi, used to be my uncle's truck 1972 chevy k10 lwb- 350,4 spd, old and tired, dad bought brand new and is now mine 1968 chevy c20 lwb- 327, 4 spd, was originally a 50th anniversary truck 1990 GMC K1500-just my runaround truck 1982 Chevy K10 shortbed, new motor and new paint, another project in the mix of the others. IMPORTS SUCK!

11-03-2002, 11:28 PM	#12
Retlaw Registered User Join Date: Sep 2001 Location: Anaheim, CA. USA Posts: 24	I found stainless steel screen at a local hardware store. I plan to use it to do the cowl on my Sub. __________________ Retlaw 69 Sub

11-04-2002, 09:08 AM	#13
bobs409 1969 Custom 30 wrecker Join Date: Sep 2001 Location: Pottsville, Pa Posts: 2,611	You can get this at any home supply place like Lowes, Home Depot, etc. It's just fiberglass replacement window screen used on storm doors and window screens. __________________ Bob 63 Impala 283/PG/3.36 (under restoration) 66 Impala 327/PG/3.36 66 Chevelle SS 409/M22/3.55 69 Chevelle 307/PG/3.08 (future restoration) 69 C10 short stepside 454/TH350/3.73 69 Custom 30 tow truck 350/4 spd/4.10 (resto done, CRUISIN TIME!) 71 Cheyenne 20 fleetside 350/4 spd/4.10 71 Chevelle 6/PG/3.08 72 Chevelle 454/M21/4.10

11-04-2002, 10:36 AM	#14
MOTHERTRUCKERS Registered User Join Date: Dec 1999 Location: BRADENTON FLA Posts: 3,269	If interested I have some unrusted cowl and firewall pieces for patching in cabs. __________________ Rest in Peace Ed. Thanks for all the good times.

11-05-2002, 11:45 PM	#15
chevyforever Some like em' long! Join Date: Nov 2002 Location: Grace, Idaho Posts: 69	thanks tons to everyone who answered my quest for help! i will be repairing the rust and getting ahold of some fiberglass screen to save my a$$ the next time around. forever __________________ 1971 chevy c10 lwb- 300 hp 350 crate motor, soon to be more with ported and polished 62cc chamber 461 double humps, TH400, 3.73 posi, used to be my uncle's truck 1972 chevy k10 lwb- 350,4 spd, old and tired, dad bought brand new and is now mine 1968 chevy c20 lwb- 327, 4 spd, was originally a 50th anniversary truck 1990 GMC K1500-just my runaround truck 1982 Chevy K10 shortbed, new motor and new paint, another project in the mix of the others. IMPORTS SUCK!



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11-06-2002, 12:05 AM	#16
Paul Clark Registered User Join Date: Apr 2002 Location: Center Point, IA Posts: 502	Sounds kinda simplistic - but What, and where the "what" was, made it rust? Eliminate the cause and the rust stays away. - At least until next winter. Uncoated metal? Sand and paint it. Leaves from trees (good source, huh)? Cut down the tree, or park someplace else. Plugged drainage holes? Don't think there are any in the cowl, but something is happening to trap moisture in there. Find that, and with a little paint, you're good to go.

11-06-2002, 08:37 AM	#17
28buick Registered User Join Date: Aug 2002 Location: east hanpton ct Posts: 26	I recently had the same problems with my 72 Blazer only worse. If you have rot by the antena you should think about removing the windshield because water pockets beneath the gasket. All these areas can be repaired if you have the time. Its also much easier if you take the fenders off because the rot tends to creep behind the fenders. I had to replace the entire windshield frame on my truck due to perpetual leaking of the top. For sealing the cowl I used anodized aluminum screen from the hardware store. It works great. Just screw it to the cab with the cowl and windshield wiper screws.

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