cab fiberglass bulge

K

Ken B

Well-known member
Oct 9, 2002
16,833
280
83
The bulge we are talking about is viewed by standing in front of the coach and looking down the trim strip from front to rear. The bulge occurs only in the front section (about 5 feet) which is made of SMC. Once you get to the joint or seam with the aluminum body you will see the rest of the coach is straight all the way to the rear. That is what we are trying to permanently fix.

Ken B.
--
Ken Burton - N9KB

76 Palm Beach

Hebron, IN
 
Ken

Pardon my ignorance, but please define SMC.

Gary
73 26' canyonland
Denison, Tx.

>
>
> The bulge we are talking about is viewed by standing
> in front of the coach and looking down the trim
> strip from front to rear. The bulge occurs only in
> the front section (about 5 feet) which is made of
> SMC. Once you get to the joint or seam with the
> aluminum body you will see the rest of the coach is
> straight all the way to the rear. That is what we
> are trying to permanently fix.
>
> Ken B.
> --
> Ken Burton - N9KB

> 76 Palm Beach

> Hebron, IN
>
>
 
Gary,
SMC is short for sheet moulding compound. It comes in a
large roll. It is preformed fiberglass, impregnated with a
heat-activated resin. They pre-cut it, and place it in huge
steam heated dies, which are in an even more huge press.
The combination of heat and pressure form a high quality
part with a nice surface on both sides. And very strong.

Gary Kosier
77 PB
Newark, Oh

----- Original Message -----
From: "Gary Cottingame"
To:
Sent: Tuesday, April 12, 2005 9:27 PM
Subject: Re: [GMCnet] cab fiberglass bulge

> Ken
>
> Pardon my ignorance, but please define SMC.
>
> Gary
> 73 26' canyonland
> Denison, Tx.
>
>

>>
>>
>> The bulge we are talking about is viewed by standing
>> in front of the coach and looking down the trim
>> strip from front to rear. The bulge occurs only in
>> the front section (about 5 feet) which is made of
>> SMC. Once you get to the joint or seam with the
>> aluminum body you will see the rest of the coach is
>> straight all the way to the rear. That is what we
>> are trying to permanently fix.
>>
>> Ken B.
>> --
>> Ken Burton - N9KB

>> 76 Palm Beach

>> Hebron, IN
>>
>>
>
 
Sheet Molded Compound = fiberglass base. I think it's a thermoset material --
put it in a 2-part mold, squeeze 'em together, heat, and get back GMC front cap,
for example. Comes in flat sheets.

That's about the limit of my knowledge. I'll bet Google knows!

Ken H.


> -----Original Message-----
> From: owner-gmclist [mailto:owner-gmclist] On Behalf Of
> Gary Cottingame
> Sent: Tuesday, April 12, 2005 9:28 PM
> To: gmclist
> Subject: Re: [GMCnet] cab fiberglass bulge
>
> Ken
>
> Pardon my ignorance, but please define SMC.
>
> Gary
> 73 26' canyonland
> Denison, Tx.
>
>

> >
> >
> > The bulge we are talking about is viewed by standing
> > in front of the coach and looking down the trim
> > strip from front to rear. The bulge occurs only in
> > the front section (about 5 feet) which is made of
> > SMC. Once you get to the joint or seam with the
> > aluminum body you will see the rest of the coach is
> > straight all the way to the rear. That is what we
> > are trying to permanently fix.
> >
> > Ken B.
> > --
> > Ken Burton - N9KB

> > 76 Palm Beach

> > Hebron, IN
> >
> >
 
>
> The bulge we are talking about is viewed by standing in front of the coach and looking down the trim strip from front to rear. The bulge occurs only in the front section (about 5 feet) which is made of SMC. Once you get to the joint or seam with the aluminum body you will see the rest of the coach is straight all the way to the rear. That is what we are trying to permanently fix.
>
> Ken B.
> --
> Ken Burton - N9KB

> 76 Palm Beach

> Hebron, IN
>
>
>
Thanks for answering, that is the same area that I was talking about.
Do you think that my approach to it would work?

I have the interior out and all the sealant removed so I see what is
going on with it. I think it is the frame causing the bulge, as the
neutral point seems to be when I jack up the front about 2"( the unit
is on 4 stands, the front 2 are placed just rear of the joint where the
front clip and the main frame are bolted together)then the bulge is
gone. It could be that when the coach is on it's wheels it will bulge
from the pressure in the other direction.

I guess I could put some dial indicators there see if that joint is
moving like I think it is.

Carleton
 
> Thanks for answering, that is the same area that I was talking
> about. Do you think that my approach to it would work?
>
> I have the interior out and all the sealant removed so I see what is
> going on with it. I think it is the frame causing the bulge, as the
> neutral point seems to be when I jack up the front about 2"( the
> unit is on 4 stands, the front 2 are placed just rear of the joint
> where the front clip and the main frame are bolted together)then the
> bulge is gone. It could be that when the coach is on it's wheels it
> will bulge from the pressure in the other direction.
>
> I guess I could put some dial indicators there see if that joint is
> moving like I think it is.
>
> Carleton

Interesting analysis. You may have hit on the problem. It sounds
like 30+ years of pounding down the highway has loosened our
joints. The same analogy could apply to me knees. But, anyway,
maybe what is needed is to jack our frames up and down till we
take the stress out of the body and then ream the bolt holes con-
necting the frame (one at a time) to the next bolt size and rebolt.
This could be why some people talk about jacking one side of the
coach and breaking the windshield.

Gary Kosier
77PB
Newark, Oh
 
Boy am I glad you guys answered that question so I do not have to show my ignorance. SMC to me is an acronym for the type of fiberglass and resin used in the construction of our end caps. I learn the acronyms and forget the meanings behind them. I guess that come from too many years in IBM (and a couple in the military). What is IBM? Hummm???

Thanks for the answer Gary and Ken.
--
Ken Burton - N9KB

76 Palm Beach

Hebron, IN
 
That is a very interesting observation and conclusion. I'm going to let the people more knowledgeable than me here reply as I am way out of my league on this issue. I just did what Gene suggested. Now I'm beginning to wonder it this was the correct fix or just a cover up of the real problem of a sagging frame connection. Another thought is: I wonder if worn out rubber body to frame isolators could have some effect on this..

Ken B.
--
Ken Burton - N9KB

76 Palm Beach

Hebron, IN
 
> -----Original Message-----
>...
> If the joint has slipped (and is still slipping), then it seems like
> we should see some evidence of it on the front-clip bolt holes.
> Reaming the holes to the next larger size and putting in tight-fitting
> bolts would certainly solve that problem, if that's really the
> problem.
>
> Rick "who never lets a Gary Kosier message get by without close
> inspection" Denney

An interesting fact, which I learned after installing two front clips: the GMC
manual says to coat the frame rails where they fit together with grease! Not
that I'm implying they should move about -- more likely the intention is to keep
them from rusting together.

Ken H. -- who pays close attention too!
 
This bulge thing:

My coach, a 1976 E2, has bulges in these front panels as well. However, I
thought that this was simply part of the design in that it got the unit
awawy from a pure slab side down the entire length of the unit and also
allowed for a slightly larger cockpit floor. Since GM regulary flared
fenders and quarter panels on their various cars, I wasn't suspicious of the
bulge. Not that I ever tested that assumption or measured anything. I also
liked the look of it. Now your telling me what I thought was design was
actually the old broad in need of serious plastic surgery to lift and
separate.

Are we sure the bulge, or flare, isn't supposed to be there? I haven't
looked at any other coaches to see if they are straight-edge flat, front to
back, or flared/bulged in this area like mine. I know that I always thought
the sides were flat until I actually got around to the paint job and the
molding. That's when I noticed that the sides in that area are actually
flared out a good bit. Anybody know for sure?

Mark Wall 76 E2 (with flared bulges that are going to stay that way)
 
Mark,

If I'd ever noticed it before, it really didn't strike me as something to
concern me or even make me wonder whether it was normal. Now I'll worry about
it 'til I do something. Like that darned engine oil temperature gauge:
ignorance was bliss, and apparently benign.

Ken H.

> -----Original Message-----
> From: owner-gmclist [mailto:owner-gmclist] On Behalf Of
> Wall, Mark
> Sent: Wednesday, April 13, 2005 6:23 PM
> To: 'gmclist'
> Subject: RE: [GMCnet] cab fiberglass bulge
>
>
> This bulge thing:
>
> My coach, a 1976 E2, has bulges in these front panels as well. However, I
> thought that this was simply part of the design in that it got the unit
> awawy from a pure slab side down the entire length of the unit and also
> allowed for a slightly larger cockpit floor. Since GM regulary flared
> fenders and quarter panels on their various cars, I wasn't suspicious of the
> bulge. Not that I ever tested that assumption or measured anything. I also
> liked the look of it. Now your telling me what I thought was design was
> actually the old broad in need of serious plastic surgery to lift and
> separate.
>
> Are we sure the bulge, or flare, isn't supposed to be there? I haven't
> looked at any other coaches to see if they are straight-edge flat, front to
> back, or flared/bulged in this area like mine. I know that I always thought
> the sides were flat until I actually got around to the paint job and the
> molding. That's when I noticed that the sides in that area are actually
> flared out a good bit. Anybody know for sure?
>
> Mark Wall 76 E2 (with flared bulges that are going to stay that way)
 
Hi Mark, after reading your email, I went out and checked my 76 E2. No
bulges. Michael

-----Original Message-----
From: owner-gmclist [mailto:owner-gmclist] On
Behalf Of Ken Henderson
Sent: Wednesday, April 13, 2005 5:36 PM
To: gmclist
Subject: RE: [GMCnet] cab fiberglass bulge

Mark,

If I'd ever noticed it before, it really didn't strike me as something
to
concern me or even make me wonder whether it was normal. Now I'll worry
about
it 'til I do something. Like that darned engine oil temperature gauge:
ignorance was bliss, and apparently benign.

Ken H.

> -----Original Message-----
> From: owner-gmclist [mailto:owner-gmclist] On
Behalf Of
> Wall, Mark
> Sent: Wednesday, April 13, 2005 6:23 PM
> To: 'gmclist'
> Subject: RE: [GMCnet] cab fiberglass bulge
>
>
> This bulge thing:
>
> My coach, a 1976 E2, has bulges in these front panels as well.
However, I
> thought that this was simply part of the design in that it got the
unit
> awawy from a pure slab side down the entire length of the unit and
also
> allowed for a slightly larger cockpit floor. Since GM regulary flared
> fenders and quarter panels on their various cars, I wasn't suspicious
of the
> bulge. Not that I ever tested that assumption or measured anything. I
also
> liked the look of it. Now your telling me what I thought was design
was
> actually the old broad in need of serious plastic surgery to lift and
> separate.
>
> Are we sure the bulge, or flare, isn't supposed to be there? I haven't
> looked at any other coaches to see if they are straight-edge flat,
front to
> back, or flared/bulged in this area like mine. I know that I always
thought
> the sides were flat until I actually got around to the paint job and
the
> molding. That's when I noticed that the sides in that area are
actually
> flared out a good bit. Anybody know for sure?
>
> Mark Wall 76 E2 (with flared bulges that are going to stay that way)
 
Hmmm, No bulges.

My coach at 36K miles had bulges. Slight but there.
They are no worse today.
If you coach doesn't have bulges take photos. we can
use them to set a standard to fix our coaches.

Mark A


__________________________________
Do you Yahoo!?
Yahoo! Small Business - Try our new resources site!
http://smallbusiness.yahoo.com/resources/
 
I have been following this conversation and looked at my coach and don't see
a bulge (it has 27,500 miles). I thought about posting a photo but have no
idea where to take it from? If somebody posted the bulge photo I could then
post the comparible.

john harper

----- Original Message -----

> Hmmm, No bulges.
>
> My coach at 36K miles had bulges. Slight but there.
> They are no worse today.
> If you coach doesn't have bulges take photos. we can
> use them to set a standard to fix our coaches.
>
> Mark A
>
>
>
> __________________________________
> Do you Yahoo!?
> Yahoo! Small Business - Try our new resources site!
> http://smallbusiness.yahoo.com/resources/
>
>
 
Mark

I think you find will a few that are straight. In my case the left side was bulged wayout the right side is only slight bulged.

Ken B
--
Ken Burton - N9KB

76 Palm Beach

Hebron, IN
 
idea where to take it from? If somebody posted the bulge photo I could then post the comparible.




John


Stand in front of the coach and take a picture looking front to rear down the long trim strip


--
Ken Burton - N9KB

76 Palm Beach

Hebron, IN
 
lolololol well that easy to say. Now this bulge appears as I understand it
at the seam of the cab to the body around the trim strip area. So do I try
to get the top to bottom of the coach in the picture or say for example 2'
above and below the trim strip. Thats why I was asking somebody to post the
actual bulge 1st then I could reproduce that same shot. I don't know how big
or how high and low on a vertical line this bulge appears. I don't see a
bulge so I don't know what your talking about "exactly"

john

----- Original Message -----
>
>
> Stand in front of the coach and take a picture looking front to rear down
> the long trim strip
>
>
> --
> Ken Burton - N9KB

> 76 Palm Beach

> Hebron, IN
>
>
 
Ok now here are some preliminary photos that are already posted. Its dark
outside right now but I posted these a couple of months ago. I'm sure this
isn't exactly what your looking for. Are there any bulge photos on the photo
site that I could look at?

http://www.gmcmhphotos.com/gallery/showpic.php?aid=934&uuid=jharper&pid=10555

http://www.gmcmhphotos.com/gallery/showpic.php?aid=934&uuid=jharper&pid=10554

john

----- Original Message -----
From: "Ken Burton"
To:
Sent: Wednesday, April 13, 2005 9:32 PM
Subject: Re: [GMCnet] cab fiberglass bulge

>
>

> conversation and looked at my coach and don't see a bulge (it has 27,500
> miles). I thought about posting a photo but have no
> idea where to take it from? If somebody posted the bulge photo I could
> then post the comparible.
>
>
>
>
> John
>
>
> Stand in front of the coach and take a picture looking front to rear down
> the long trim strip
>
>
> --
> Ken Burton - N9KB

> 76 Palm Beach

> Hebron, IN
>
>
 
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