What is this stuff?

K

Ken B

Well-known member
Oct 9, 2002
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I have run into this stuff many times on cars but do not know what it is or where to get it. It is a black goo like sealer that is used by car
manufacturers on seams and holes. I just ran into it again when working on my clearance lights. It was used to seal the holes where the clearance
light wires run through the roof. I saw it also a couple of years ago used to seal a drain hose to the body and fender liner in the left rear fender
well.

This stuff never fully hardens and after 40 years it is still flexible. I doubt it is flexible enough to be used in a caulking gun. I currently
still have some it smeared on my finger from working on those holes. It does not come off easily. I imagine paint thinner might cut it. I haven't
tried it.

Is it the same stuff that is used to seal in windshields?

What is it and where do I buy it?
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 
Hello Ken, I believe the stuff you are looking for is in fact automotive seam sealer.

Here is a link to the product I'm referring to... https://www.napaonline.com/en/p/MMM08367

There other colours available so have a look at the NAPA website for options.

I have used it many times with good results, hope this helps.

Regards,
Mike
 
Ken,

I can't remember what it is called but it comes in strips about 1/8" OD and
12" long. They are layered in a box with each layer separated by a wax
paper. Ken H. told me to use it around the passenger and driver side windows
between the metal and the body.

I bought it at an auto body supply store that sold auto paint, sandpaper,
adhesives, etc.

Regards,
Rob M.
The Pedantic Mechanic
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808

-----Original Message-----
From: Gmclist [mailto:gmclist-bounces] On Behalf Of Ken
Burton
Sent: Sunday, April 30, 2017 6:13 PM
To: gmclist
Subject: [GMCnet] What is this stuff?

I have run into this stuff many times on cars but do not know what it is or
where to get it. It is a black goo like sealer that is used by car
manufacturers on seams and holes. I just ran into it again when working on
my clearance lights. It was used to seal the holes where the clearance
light wires run through the roof. I saw it also a couple of years ago used
to seal a drain hose to the body and fender liner in the left rear fender
well.

This stuff never fully hardens and after 40 years it is still flexible. I
doubt it is flexible enough to be used in a caulking gun. I currently
still have some it smeared on my finger from working on those holes. It
does not come off easily. I imagine paint thinner might cut it. I haven't
tried it.

Is it the same stuff that is used to seal in windshields?

What is it and where do I buy it?
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 
Rob's correct, and the stuff is called butyl mastic, which never cures and remains sticky and workable for many years. It comes in strips or rolls, with each layer separated by paper.

Residue is easily cleaned up with mineral spirits or similar solvents.

http://www.devansealants.com/specialty-sealants-and-adhesives/butyl-mastic-tape/

Les Burt
Montreal

>
> Ken,
>
> I can't remember what it is called but it comes in strips about 1/8" OD and
> 12" long. They are layered in a box with each layer separated by a wax
> paper. Ken H. told me to use it around the passenger and driver side windows
> between the metal and the body.
>
> I bought it at an auto body supply store that sold auto paint, sandpaper,
> adhesives, etc.
>
> Regards,
> Rob M.
> The Pedantic Mechanic
> USAussie - Downunder
> AUS '75 Avion - The Blue Streak TZE365V100428
> USA '75 Avion - Double Trouble TZE365V100426
> USA '77 Kingsley - TZE 267V100808
>
> -----Original Message-----
> From: Gmclist [mailto:gmclist-bounces] On Behalf Of Ken
> Burton
> Sent: Sunday, April 30, 2017 6:13 PM
> To: gmclist
> Subject: [GMCnet] What is this stuff?
>
> I have run into this stuff many times on cars but do not know what it is or
> where to get it. It is a black goo like sealer that is used by car
> manufacturers on seams and holes. I just ran into it again when working on
> my clearance lights. It was used to seal the holes where the clearance
> light wires run through the roof. I saw it also a couple of years ago used
> to seal a drain hose to the body and fender liner in the left rear fender
> well.
>
> This stuff never fully hardens and after 40 years it is still flexible. I
> doubt it is flexible enough to be used in a caulking gun. I currently
> still have some it smeared on my finger from working on those holes. It
> does not come off easily. I imagine paint thinner might cut it. I haven't
> tried it.
>
> Is it the same stuff that is used to seal in windshields?
>
> What is it and where do I buy it?
> --
> Ken Burton - N9KB
> 76 Palm Beach
> Hebron, Indiana
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
Keith Weeks | 1402 So. Cage Blvd., Unit 273, Pharr, Texas 78577
612.978.7243


>
> Hello Ken, I believe the stuff you are looking for is in fact automotive seam sealer.
>
> Here is a link to the product I'm referring to... https://www.napaonline.com/en/p/MMM08367
>
> There other colours available so have a look at the NAPA website for options.
>
> I have used it many times with good results, hope this helps.
>
> Regards,
> Mike
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
I know the stuff you're refering to Ken, you see it in numerous places. It may be butyl but certainly has a different consistency than the butyl on
the rolls I've used. It seems to have more of a tar consistency. No help on the product name though.
Hal
--
1977 Royale 101348,

1977 Royale 101586, Diesel powered,

1974 Eagle Bus 45',w/slideout
 
Thanks for all of the answers. Is this the same stuff that Gene Dotson was supplying by the roll for sealing CR Lawrence windows?

I have a small remainder of a roll that came from my windshield installation buddy. I tore off little strips about 2.5 inches long and formed it to
seal the holes under the clearance lights. I have only done 4 of them so far.

The 5th one is going to be a bear. Both screws are rusted and it is up against my awning. I have it soaking in Kroil right now. I found that
heating the screws for 4 or 5 minutes with a soldering iron and then shock cooling the screws with Kroil worked well for getting out the rusted
screws. Before I did this I could not get them loose with a set of needle nose vice grips. After heating and oiling with Kroil a few times they
turned easily with a pair of pliers. Let's hope hope I have the same luck with the final one on the rear.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 
I believe the butyl mentioned above in the this thread is what you are
referring to Ken. Back in the day windshields and back glass auto glass was
installed with this material. It can be purchased in coiled ropes of
various diameters ( 1/4",5/16",3/8" being the most common). It is also
available in rolled strips typically 1/8" thick and varying width which
would be used for rv windows and other protrusions like furnaces and vents.
It is available in block form at home depot which is super handy for
packing bigger holes like the ones in the rear floor at the joint between
the rear body and corner smc panels. I have had two gmcs and both if them
had gaps in this area which created a super convenient pathway for mice.

Sully
77 eleganza 2
Seattle

> Thanks for all of the answers. Is this the same stuff that Gene Dotson
> was supplying by the roll for sealing CR Lawrence windows?
>
> I have a small remainder of a roll that came from my windshield
> installation buddy. I tore off little strips about 2.5 inches long and
> formed it to
> seal the holes under the clearance lights. I have only done 4 of them so
> far.
>
> The 5th one is going to be a bear. Both screws are rusted and it is up
> against my awning. I have it soaking in Kroil right now. I found that
> heating the screws for 4 or 5 minutes with a soldering iron and then shock
> cooling the screws with Kroil worked well for getting out the rusted
> screws. Before I did this I could not get them loose with a set of needle
> nose vice grips. After heating and oiling with Kroil a few times they
> turned easily with a pair of pliers. Let's hope hope I have the same luck
> with the final one on the rear.
> --
> Ken Burton - N9KB
> 76 Palm Beach
> Hebron, Indiana
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
Ken, it's also supplied with coax grounding kits and some fittings. Andrew Corporation would know what it is, and probably a source.

--johnny
--
76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
"I forgive them all, save those who hurt the dogs. They must answer to me in hell" - ol Andy, paraphrased
 
Thanks. I have some of that stuff around that is used for outdoor coax sealant.
--
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
 
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