[GMCnet] hood hole repair

[Keith V]

So what the best way to repair holes in the hoods?
I am removing the GMC logo, the POs locks and maybe hidden latches.
So some small holes but those lock holes are a good 1/2"

I'm thinking some aluminum disks with JB weld or something?
--
Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
69 Vette
29 Dodge



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[Jon Roche]

West systems epoxy. Use a ear plug soaked in the epoxy. Or sponge for bigger holes.


--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/

[Emery Stora]

Thanks to Dale Ropp for that method that he invented and detailed in a presentation several years ago at a GMCMI convention.

Emery Stora
77 Kingsley
Frederick, CO

[Keith V]

Thats fine for a small hole, but what about one thats 1/2" across?
My ears arent that big

--
Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
69 Vette
29 Dodge

[Emery Stora]

That is why Jon said to use a piece of sponge for larger holes.
Or you could epoxy a small piece of fiberglas cloth to the back and then fill the depression with bondo or with JB Weld and sand it level with the surface.

Emery Stora

[Matt Colie]

Keith V wrote on Sun, 18 September 2016 10:35

> Thats fine for a small hole, but what about one thats 1/2" across?
> My ears arent that big

Kieth,

If you don't want to do it in two steps, (i.e. span with glass cloth and fill later) then use this cheap, sleezy and very effective plan:
Find a piece of something as a backer to put inside.
Cover it with something - old poly grocery bag will work. (I have expensive non-stick fabric I would use.)
Sand and clean the back side. And acetone wash is require because of the primitive SMC.
Mix epoxy and coat the all the inside surfaces including the hole edge.
Soak the tiny piece of glass cloth. (If you don't have, I can mail you some.)
Stick the cloth over the hole.
Put the block against it and secure it there with clamps or tape.
Fill the remaining epoxy with microlight or filleting blend to well thick of peanut butter.
Now fill in the hole.
If you don't have a cover block or tape of something and you rushed things a little, the filler might try to run out of the hole. You can block the
door horizontal or cover it with another block like the one below.

The filled epoxy will sand or file much more easily the solid epoxy. West System stuff is much easier and more reliable than any of the polyester
body fillers. It may be more expensive, but it is still cheaper than re-doing it because the polyester tripped too soon or not at all.

Matt - the offer was real.
--
Matt & Mary Colie - Members GMCMI, GMCGL, GMCES
'73 Glacier 23 - Still Loving OE Rear Drum Brake with Applied Control Arms
Now with both true Keyless and remote entry
SE Michigan - Twixt A2 and Detroit

[Paul Zerkel]

I have bought West Systems stuff from Jamestown Distributors. For a long time I was intimidated and afraid to try it. I did buy the pumps (highly
recommended). Once I finally got the courage up, I found the stuff quite easy to work with. They have lots of helpful how-to videos on their site.

Anyway, lately I noticed Jamestown has been heavily promoting their private label "TotalBoat" brand epoxy. Supposedly it is compatible with West
Systems (as in you can mix/match Epoxies and hardeners). The TotalBoat stuff comes in plastic jugs instead of metal cans, has its own set of pumps
available, but is significantly cheaper.

Has anyone tried the "TotalBoat"? I have enough of the West systems on hand now for several future minor repairs, so see no need to switch at this
time.
--
Paul Zerkel
'78 Eleganza II
Salisbury IL (near Springfield)

[Keith V]

Wait, what? the hoods are SMC?
I thought they were pot metal!

I know how to work with SMC, I have a Vette :)
I'll basically do what Matt described, it's not hard at all IMHO

--
Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
69 Vette
29 Dodge

[Jon Roche]

Keith,

since you are a SMC expert take your coach up to my place, and you can help me patch up my coach as well. my rear marker light, and where my
ladder mounts needs some repair. I patched a couple other holes on the side of my coach, and what a mess and pain that was for me!

Yes- Dale Ropp has to get the credit for the west systems epoxy repair using sponges and ear plugs. I have used that on a couple things, but ran
out of the epoxy samples he was giving out, and have not quite spent the money on more. I need to, I could of used some epoxy yesterday as well on
another project.

--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/

[Matt Colie]

Keith V wrote on Sun, 18 September 2016 21:55

> Wait, what? the hoods are SMC?
> I thought they were pot metal!
>
> I know how to work with SMC, I have a Vette :)
> I'll basically do what Matt described, it's not hard at all IMHO

Keith,

The two engine hoods, the propane locker and generator doors are all SMC. Nothing exterior (that I have run into) is potmetal.

Matt

--
Matt & Mary Colie - Members GMCMI, GMCGL, GMCES
'73 Glacier 23 - Still Loving OE Rear Drum Brake with Applied Control Arms
Now with both true Keyless and remote entry
SE Michigan - Twixt A2 and Detroit

[Keith V]

Jon,
I could do that, sounds like fun. Now we just have to find time lol

I think the end caps are plain old fiberglass right? That stuff is easier, SMC does require a different system due to the build in mold release, but it's still pretty easy. Yes it's messy and scary as you have to make a big mess to do it right. I use my 4" grinder and feather the repair for at least 2" on each side, thats a big hole, then fill with glass matt, the non woven stuff or you will see the weave through the repair. More important for a corvette than a GMC, but zero effort or cost difference. Fill the hole with fiberglass using bigger pieces as you fill. small pieces in the bottom, bigger at the top. I try to do it all in one shot for a better bond.

Let that cure, hit it with the 4" to take off any high stuff, then fill with a short strand filler. Sand and contour with 80 grit, then top it with your favorite bondo and then scratch filler.

I'm a fan of eastwood products for fiberglass myself if you want to do it right :D

----------------------------------------

[Todd Sullivan]

There is no fiberglass on the gmc. It's either aluminum or smc unless
aftermarket parts have been added.

Sully
77 eleganza 2
Seattle

[RC Jordan]

Like many of the boaters here, I've been using West System for around 30 yrs, usually keeping a couple of gallons on hand. I mess with some antique
sailboats. But, if you need any quantity, it really hits the wallet. A few months ago, in some searches about dynel, I ran across several pro
boatbuilders recommending Fasco, syaing they have used it long-term. I've just received a couple of gallons of various types, but haven't cracked the
lids yet. Take a look at the pricing
http://fascoepoxies.com/


For my go-to material for small patches used to be Marine-Tex. But --and this very well might be just me-- I'm having problems with it setting up
properly, so I'm switching to JBweld Marine to try that.

Tip: Save your old venetian blinds. The old blind slats make a great fairing batten.

Tip2: Rather than a sponge, go to a big box and buy a 3m pad for a commercial floor polisher and cut them up for matrix. Also makes for cheap 3m
scrubbing pads, just whack off what you need.

Tip3: Instead of fiberglass tape fabric, get a roll of fiberglass mesh drywall tape. Use a couple of layers if you want a tighter weave. Bonus: It's
slightly sticky on one side so you can lay it easily. Also, very thin, so you don't have too much buildup. AND, it doesn't fray much at all, so no
loose threads around the edges.


--
77 Royale Coachmen Side Dry Bath
76 Birchaven Coachmen Side Wet Bath
76 Eleganza
Elizabeth City, NC

[Matt Colie]

Keith V wrote on Mon, 19 September 2016 10:17

> Jon,
> I could do that, sounds like fun. Now we just have to find time lol
>
> I think the end caps are plain old fiberglass right? That stuff is easier, SMC does require a different system due to the build in mold release,
> but it's still pretty easy. Yes it's messy and scary as you have to make a big mess to do it right. I use my 4" grinder and feather the repair for
> at least 2" on each side, thats a big hole, then fill with glass matt, the non woven stuff or you will see the weave through the repair. More
> important for a corvette than a GMC, but zero effort or cost difference. Fill the hole with fiberglass using bigger pieces as you fill. small pieces
> in the bottom, bigger at the top. I try to do it all in one shot for a better bond.
>
> Let that cure, hit it with the 4" to take off any high stuff, then fill with a short strand filler. Sand and contour with 80 grit, then top it
> with your favorite bondo and then scratch filler.
>

> I'm a fan of eastwood products for fiberglass myself if you want to do it right :d

Keith,

I'm going to have to work in here slowly. My cold has gotten bad enough that the exercise of using a keyboard is tiring.

First, with epoxy - No epoxy, not just West - Never Use non-woven mat. That is for poly and vinylester resins both of with have an acetone carrier
for the catalyst. That mat is bonded with a material that is soluble in acetone. That material interferes with the epoxy bonding to the glass
fibers.

Never buy fillers again. Use the epoxy and what ever fill material you want (West has a bunch). Filleting blend and Microlight are the two that do
car stuff real well. Want it to level on a flat surface? Just mix it kind of thin and let it settle. Want to hang it upside down? Put on a very
light coat of unfilled epoxy and then put filler in the mix until you can't stir it.

One important thing is to wash the surface of cured epoxy as it pushes out an amine blush that is a great release agent.

The only thing I haven't done successfully with the West stuff I keep on hand is spot and scratch fill. So, I buy a tube every other year. (Well,
not any more as I don't do much of that these days.)

Matt

--
Matt & Mary Colie - Members GMCMI, GMCGL, GMCES
'73 Glacier 23 - Still Loving OE Rear Drum Brake with Applied Control Arms
Now with both true Keyless and remote entry
SE Michigan - Twixt A2 and Detroit

[Matt Colie]

pzerkel wrote on Sun, 18 September 2016 21:54

> I have bought West Systems stuff from Jamestown Distributors. For a long time I was intimidated and afraid to try it. I did buy the pumps (highly
> recommended). Once I finally got the courage up, I found the stuff quite easy to work with. They have lots of helpful how-to videos on their site.
>
> Anyway, lately I noticed Jamestown has been heavily promoting their private label "TotalBoat" brand epoxy. Supposedly it is compatible with West
> Systems (as in you can mix/match Epoxies and hardeners). The TotalBoat stuff comes in plastic jugs instead of metal cans, has its own set of pumps
> available, but is significantly cheaper.
>
> Has anyone tried the "TotalBoat"? I have enough of the West systems on hand now for several future minor repairs, so see no need to switch at this
> time.

Paul,

Much as I expected, Gougeon knows about Total Boat. The response I got from my tech guy was that they have found not bond issues when used with West,
but that the components are not compatible.
This is no particular surprise.

Matt



--
Matt & Mary Colie - Members GMCMI, GMCGL, GMCES
'73 Glacier 23 - Still Loving OE Rear Drum Brake with Applied Control Arms
Now with both true Keyless and remote entry
SE Michigan - Twixt A2 and Detroit

[Keith V]

Ive had good luck with evercoat ( not eastwood ) SMC resin, and the Vette guys like it. Besides I have a bunch So I'll be using that.
Epoxy may be better, but id rather not buy more since my garage is pretty much full.

----------------------------------------

[Emery Stora]

Since Evercoat is a polyester compound it does not bond well with SMC long term. There is an article in a past issue of GMCMI newsletters that I wrote several years back that explains why polyester resins don’t bond well with SMC. If anyone needs the link to the article let me know.
Epoxy is the only resin that will last long term.

Emery Stora
77 Kingsley
Frederick, CO

[Todd Sullivan]

After a little web research and a phone call to Evercoat it appears there
is only ONE epoxy based resin system that Evercoat makes. Its called
Everfix and available in quart and gallon kits. It is available at
Wallmart, Oreilly's and other retailers.

Sully
77 eleganza 2
seattle

[Todd Sullivan]

Sorry for the bunches of short posts but I am trying to work while also doing light research on this topic on the side. Most of the larger chemical
companies marketing resin and repair products towards SMC repairs tout Polyester resin systems. Some of these systems are listed as "hybrid" systems.
This includes Evercoat, 3M, and USC. I have used 3m 8115 which is a two part epoxy panel bonding adhesive extensively in larger repairs on The Pig. It
worked well but this epoxy requires an expensive precision mixing application gun which could be cost prohibitive to many who wish to undertake these
types of repairs in a limited frequency. Furthermore I found it challenging to dispense and saturate fiberglass matting with this product due to its
thick viscosity. While the gravity defying benefits of the 8115 make it easy to keep in place compared to a thinner viscosity resin, the lack of
wicking or saturation creates other issues such as longer application times and excessive build of the epoxy while attempting to mechanically force
the product into the patch material fibers. I would love to read the technical info you have on smc and epoxy topic Emery as now I am quite curious.
--
Sully
77 Royale (The War Pig)
77 Eleganza 2 ( Recherché )
Seattle, wa
Future land speed record holder fully equipped motorhome (bucket list)

[Gary Worobec]

You might want to check out the THE COMPOSITES STORE in Tehachacpi, CA. http://www.cstsales.com <http://www.cstsales.com/>
They have small batch epoxies, carbon fiber, frp or pretty much anything else you need.

Gary and Joanne Worobec
Anza, CA
1973 Glacier 23

[Espen Heitmann]

Emery please give me the link as I need to read up a bit on SMC, I have the 3M 8115 that I will use to glue a couple of panels back on bu I bought a
can of U-pol SMC filler for other repairs (
http://www.ebay.com/itm/U-pol-SMC-1-1Ltr-Black-High-Adhesion-Easy-Sand-Plastic-Bumper-Filler-BEST-Price-/221792843460?hash=item33a3e236c4:g:GOsAAOxyJypTk57S
)but that is of course polyester based..
--
1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green Machine,
And just sold my 1973 26'-2 # 581 White Canyon lands under the name Dobbelt trøbbel
in Norway

[Emery Stora]

Instead of giving the link I can summarize the article in this email.

SMC is actually polyester based but the way GM incorporated the mold release agent during manufacturing makes polyester resin a poor choice for repair. Here is the article that I wrote for the GMCMI newsletter issue 96, Summer 2006, that might be of some interest to you.

The earliest 1973 vehicles have “hand laid” fiberglass, at least for the front body assembly. Somewhere between serial number 24 and 50 this process became SMC (sheet molded compound). This was a new composite material for use in the automotive, industrial, and personal watercraft markets that presents unique repair problems. Parts made with SMC are produced in compression molds, so they are smooth on both the inside and outside. SMC parts do not have an outer gel coat, but they are usually painted or color molded. When the paint is sanded off, the underlying surface has a marble appearance. When damaged SMC is sanded, short coarse fibers are exposed and a dryer powdery dust is produced compared to conventional materials.SMC is a polyester-based material, but it cannot be repaired with polyester resin. This is due to the mold release agent that is present throughout the entire SMC part. Unlike conventionally molded parts where release agents are applied to the mold surface, SMC is compounded with them in the resin mix for quicker processing. This means that as the damage is sanded to prepare a good bonding surface, fresh mold release agent is exposed. Polyester resin products are not strong enough to adhere to this surface. SMC SHOULD ONLY BE REPAIRED USING EPOXY-BASED RESINS, FILLERS AND ADHESIVES. For good adhesion, when painting, use only catalyzed type paint systems -- at least for the primer.When a part is broken or crushed, it is difficult to realign the pieces with each other because the frayed fibers tend to “hang up” on one another. Use a saw blade to cut the length of cracks or tears. This relieves the stress on solid laminates which often return to their original shape with little force. A router is excellent for removing damaged core material without disturbing intact face skins. Try to remove as little material as possible so the repair does not grow too large. However, solid laminate must be exposed for a good repair.Next, support the part so nothing gets distorted during the repair process. This can be as simple as strips of 2 inch wide masking tape or as elaborate as a custom-made clamping fixture. With the part supported, proceed to preparing the bonding surface by grinding a taper or steps around the damage. This is the critical step for functional repairs but it is also the most overlooked and abused. If a taper is to be used, measure the depth of the valley and calculate how far the sanding must extend to achieve the desired ratio. Mark the outer edge of the taper using a marker and begin sanding inward toward the valley. Be sure to remove material slowly so the taper progresses evenly. Wet the entire bonding area with resin, then begin saturating each ply of reinforcement before it is placed. Work on a sheet of plastic so the fabric can be easily lifted from the table once it is ready. A flexible rubber squeegee is the best tool for spreading the resin evenly through the fabric and removing excess which may be present. Place the reinforcement into its spot on the repair, ensuring the proper orientation. Stop every few layers to compact the patch as much as possible. A squeegee or grooved roller works well for this. Continue stacking the repair plies at right angles until all the material that was removed has been replaced. A final cover layer is then added over the entire area. Sand before painting.

Emery Stora

[Espen Heitmann]

Thank you Emery

The next question then is why a company sells polyester based fillers for SMC repairs ?
I will start repairing a panel this weekend if I have the time and try some of the filler i have just to see how it works, I will glue in some
aluminum reinforcements with the 8115 anyways and the filler will not be used on anything critical or places it will be seen when I am done

[Emery Stora]

I would guess that the polyester fillers would work fine if it were not for the way that GM mixed the mold release agent into the whole mix.
Other companies may not do it that way in their SMC parts.

Emery Stora

[Todd Sullivan]

8115 has small glass spheres in it to maintain minimum material thickness
for bond joint strength. The spheres prevent excessive squeeze out from
clamping. These spheres also make 8115 more difficult to work with when you
are attempting to saturate stranded material. If full saturation is not
achieved there will be a resulting lack of strength of the finished repair
and "dry spots" within the matting which can be seen when the repair is
ground back for final cosmetic finishing with plastic body filler. If I
were to perform a structural repair over a larger area (6+ inches) I would
find a scrap piece of gmc smc with the same contour or if that was not
available use a piece of aluminum sheet formed to the curve of the panel
and bond THAT to the backside of the repair area with 8115. At this point
your structural stability has been restored and the remaining cavity on the
cosmetic side can be filled with the filler of your choice.

Sully
77 Royale
Seattle

On Wednesday, September 21, 2016, Emery Stora <emery...@mac.com> wrote:

> I would guess that the polyester fillers would work fine if it were not
> for the way that GM mixed the mold release agent into the whole mix.
> Other companies may not do it that way in their SMC parts.
>
> Emery Stora
>
> > On Sep 21, 2016, at 2:50 PM, Espen Heitmann <bi...@online.no

[Keith V]

They claim they have additives that allow the polyester to bond to SMC

[Todd Sullivan]

I do t think the smc is the issue but the gmc specific smc like Emery said.

Sully
77 eleganza 2
Seattle

[Emery Stora]

But, if you have a choice why use polyester instead of epoxy?
We all know that epoxy is much stronger than polyester.
Is it because you don’t want to pay the little bit more that epoxy costs?

Emery Stora
77 Kingsley
Frederick, CO

[James Hupy]

For my money, the epoxies are far easier to mix (50/50) accurately, much
stronger, stick to almost anything, and dry more predictably than polyester
resins. I have occasional uses for them, and I have had issues with
polyester when they get a bit older in the can, not curing up quickly, or
setting off before I work them completely. Epoxies will work with anything
including carbon fiber. My choice anyway. Listen to Todd Sullivan, he makes
his living with that stuff.
Jim Hupy

[Todd Sullivan]

Why use polyester over epoxy? If I am after a cosmetic repair then filling in areas for cosmetic correction ONLY with epoxy will take longer to apply
and cure as well as sand to contour( at least the epoxys I have used) then you add to that the material cost difference which can be 5 times or more.
One of the challenges I encountered while restoring all of the damaged bodywork on The Pig was access. A lot of the areas I needed to repair I could
not access from the backside. In that situation I was forced to complete a structural repair at the same time as the cosmetic. The only means I could
come up with to accomplish this was to aggressively bevel the panel outward from the damage area and fill it with fiberglass sheet impregnated with
epoxy. If the damage is properly reinforced from behind with a suitable patch panel adhered with a suitable cross bonding adhesive (epoxy)any "bondo"
type product used to fill the front to final contour which is compatible with your chosen topcoat system will work just fine.
my 2c

--
Sully
77 Royale (The War Pig)
77 Eleganza 2 ( Recherché )
Seattle, wa
Future land speed record holder fully equipped motorhome (bucket list)

_______________________________________________