Author Topic: How to repair plastic/vinyl air dam (69 BB w/ AC) (Read 45963 times)

jvb6648 · « **on:** April 18, 2011, 01:23:21 AM »

I have this air dam that goes under the front of the sub frame. It's made of plastic or vinyl. Does anyone know how I can repair the tears at the mounting holes. Some type of glue, epoxy or plastic weld?

<edited title - Kurt>

x66 714 · « **Reply #1 on:** April 18, 2011, 07:50:40 PM »

Looks like a piece for a big block a/c 69 Camaro....Joe

68Zproject · « **Reply #2 on:** April 18, 2011, 10:17:22 PM »

I'm no expert at this, but I repaired the rotted floor of my 1950 Buick with fiberglass mat and resin. I would think you could use that on the plastic to repair holes as it sands very well and molds to anything.

jacmac · « **Reply #3 on:** April 18, 2011, 11:20:46 PM »

You are a lucky man to have one of those shields,been looking for one for yrs.Not really sure how to fix it, maybe some one will chime in.

Sauron327 · « **Reply #4 on:** April 19, 2011, 12:27:48 AM »

3M makes plastic weld sticks and two part repair and bonding agents for a multitude of auto applications and material compositions, such as polypropolene, FRP, ABS and others. Bumper covers, rigid or semi are often repaired with some of them. Available on line or just go to your jobber. 3M Scotchweld DP 8005 may be applicable, double check. Fiberglass resin, mat or cloth is best used to repair itself or for use in laminations.

IZRSSS · « **Reply #5 on:** April 19, 2011, 12:41:50 AM »

Jim,

Your shield is certainly a very unique and very cool piece. It looks like you have the entire front flange w/3 holes missing, 2 holes missing or plugged in the center, and the 2 holes you do have at the back end need to be beefed up a bit. The 2 holes at the outer edge flanges look fine.

There are several products listed for plastic repair such as; Mxbon 105 (professional cyanoacrylate adhesive), 3m--Dura Mix (autobody supply.net), & Plastic Weld (Napa)...however, I like the advise given for fiberglass mat & resin.

As difficult as this part is to find I would highly recommend drilling reputable body shops before you decide what course of action to take. To make matters worse, the shields original configuration needs attention as well.

Good luck

Sauron327 · « **Reply #6 on:** April 19, 2011, 12:49:18 AM »

I don't believe fiberglass resin will work better than a product made for a particular material. These products are made for superior adhesion, strength and workability. I've used them many times in collision repair and they work extremely well. Torn bumpers are heated, braced, bonded, filled, primed and painted for an undetectable repair. Bodyshops and other industries use these products on a daily basis. Jobbers carry these products and are aware of their applications.

IZRSSS · « **Reply #7 on:** April 19, 2011, 12:52:27 AM »

Good point...we posted up at about the same time and I didn't read what you had to say...

What would be your advise for adding or splicing material that is missing? For example...the entire front flange (or at least most of it)? And...would heat work to reconfigure the angle of the back portion?

Sauron327 · « **Reply #8 on:** April 19, 2011, 12:58:29 AM »

Quote from: IZRSSS on April 19, 2011, 12:52:27 AM

Good point...we posted up at about the same time and I didn't read what you had to say...

What would be your advise for adding or splicing material that is missing? For example...the entire front flange (or at least most of it)? And...would heat work to reconfigure the angle of the back portion?

We used to to graft on a donor portion for larger missing pieces. If he did not want to tackle it himself, a shop could handle it.

jvb6648 · « **Reply #9 on:** April 19, 2011, 02:34:16 AM »

Thanks for all the tips, especially the assembly drawing. The front flange is there it just doesn't show at that angle.

KevinW · « **Reply #10 on:** April 19, 2011, 11:32:22 AM »

Those parts should be an ABS plastic, I would not recommend a fiberglas product. Fiberglass resin is stiff, ABS is piable. The resin will crack when the ABS starts to flex. The best choice of action is to use ABS repair. you can use doner ABS panels (from modern cars, like wheelwell liners) for replacing missing areas. Read up on plastic welding (like this site http://www.plasticweldingandtools.com/) You need to correctly identify the plastic and use filler rods of the same material (just trim some thin shards off doner parts) and use soldering iron to soften the fillers. There are some you-tube videos on plastic welding. Luck!

77thor · « **Reply #11 on:** April 19, 2011, 01:28:26 PM »

Wow. I didn't even know those existed, and I certainly have never seen one before.

jvb6648 · « **Reply #12 on:** April 20, 2011, 03:19:16 AM »

It has a part number but I couldn't tell you what it is. They were used on the Trans-Am race cars. I got that from a friend whose boss' brother worked on a Trans-Am team.

IZRSSS · « **Reply #13 on:** April 20, 2011, 10:48:52 AM »

According to the AIM, these shields were only available for the 396's & the 427.

x66 714 · « **Reply #14 on:** April 20, 2011, 11:18:17 AM »

And only used with C-60, air conditioning & only in 1969 with the 396 as Marty stated....Joe

JoeC · « **Reply #15 on:** April 20, 2011, 01:24:17 PM »

I have done some repairs on old dirt bike plastic where I cut and fit in a "I" shape patch. I used plastic of same thicness (scrap piece from newer car bottom shield) and fit it and glue it. The shape of the patch holds it together and the glue just holds the patch in place.
I used a 3M glue from auto parts store that is used to glue on emblems. After sanding and painting they looked good.

9T4Z · « **Reply #16 on:** April 21, 2011, 10:57:01 PM »

I have successfully done numerous plastic repairs. Fiberglass patch will not work and make a mess. Polyethylene repairs successfully with heating donor patches. ABS and some mixed composite plastics repair extremely well with plumbing cement. There are PVC (polyvinyl chloride) and ABS cements that will literally cold weld parts together. I agree you should do your research and try a small area to assess your results... but if you get the right material and cements together you will amaze yourself... find some donor material and try it on an edge you can cut off if not successful. Where appropriate you can overlap material to reinforce it adjacent to the missing/damaged bolt holes. Do not be afraid to ask a body shop for advice as this part is certainly quite rare.

Good luck,

BlackoutSteve · « **Reply #17 on:** April 22, 2011, 02:34:13 AM »

I have found that if the plastic is ABS, Plastex work the best and is easiest to apply. http://www.plastex.us/PLASTEX/index.html

I have modified my Vintage Air evaporator's ABS plastic housing and converted my repro dash carrier with the stuff, among other things too.
Scroll this post.. http://www.usmuscle.com.au/Forum/showpost.php?p=15047&postcount=97
and http://www.usmuscle.com.au/Forum/showpost.php?p=29543&postcount=294
and http://www.usmuscle.com.au/Forum/showpost.php?p=30334&postcount=335 including much of the rear vent and heater control that wasn't photographed. (was done prior to getting a camera!)

Also, after the on-line enquiries that I have made regarding the 3949856 sheild, I doubt it was fitted to any Camaro, let alone a BB-A/C Camaro at all.
The only ones I have been shown by the on-line "Camaro community" were off Novas and other similar models, but never Camaros.

How many BB A/C Camaros were built and are still owned in OE condition, with not one owner prodiving an OE image of one on the car or at least a pic of all the 9 mounting holes on support and subframe from where it had been installed?
Seems awfully strange to me.

NoYenko · « **Reply #18 on:** October 06, 2011, 02:07:17 PM »

JVB, I & many others have been looking for one of these original shields. That is a very rare part. Would you be interested in selling it or loaning it out to be reproduced? It doesn't look too bad from the picture. George

KurtS · « **Reply #19 on:** October 06, 2011, 06:10:11 PM »

I personally doubt it was used much in TA racing - cooling wasn't a huge issue for most cars, it would be in the way, and it wouldn't hold up.

I think this is the 2nd or 3rd one I've ever seen. I wonder if they were used in production the whole year or not.

x66 714 · « **Reply #20 on:** October 06, 2011, 06:24:37 PM »

Kurt
Mine is an 08E of 1969 & it had it. I've aquired a repacement for it as it was gone but all the bolts were there. I'm unable to read the date on that posted page, C60,B4. They would've been after that date...right?....Joe

NoYenko · « **Reply #21 on:** October 06, 2011, 07:24:55 PM »

I am taking my car apart to restore and was going to send core support out for powder coat. I thought I had 3 extra holes in the bottom of support and about to weld them up. Checked the manual and found they are supposed to be there. Now feel I need to find the shield. My car was made 1st week in Nov.1968 and appears to have had it. Hope we can find someone to reproduce it.

jacmac · « **Reply #22 on:** October 06, 2011, 10:50:39 PM »

My 04C had one

If someone would reproduce it, I would probably buy one.In 1976 went to the chevy dealer to get one ,they had know idea what I was talkng about!!

big iron · « **Reply #23 on:** October 06, 2011, 11:35:54 PM »

Joe,
That was a redesign which means there had to be an earlier design. I guess they could have changed the mounting of the shield.
Bob

Quote from: x66 714 on October 06, 2011, 06:24:37 PM

Kurt
Mine is an 08E of 1969 & it had it. I've aquired a repacement for it as it was gone but all the bolts were there. I'm unable to read the date on that posted page, C60,B4. They would've been after that date...right?....Joe

x66 714 · « **Reply #24 on:** October 07, 2011, 03:17:04 AM »

There is a guy who has made a few of these & I got one of his first ones. I will call him tomorrow & see if he's ready to start releasing them. After that I will see how he want those needing them to contact him.....Joe

x66 714 · « **Reply #25 on:** October 07, 2011, 02:06:24 PM »

Those of you wishing to purchase a new reproduction can contact Ed at edmelberg@zoominternet.net. Leave your phone number & he will call you back. They are very nice. He has about 36 left. Regretably with the low demand & the expense of making these the cost is a little up there...Joe

NoYenko · « **Reply #26 on:** October 07, 2011, 10:24:52 PM »

Joe
Was your repro made out of plastic or metal,and do you think it looks like the originals?

x66 714 · « **Reply #27 on:** October 08, 2011, 01:01:24 AM »

It looks like pictures I've seen of an original. It's vacuum formed abs plastic as were the originals. The two guys behind this sure did their home work. I only had pieces of the original that I used to compare the thickness. My original question here a while back was "did it really exist."
I'm glad to have one as I never expected to find one & it's not an item that most of the repop houses would do because of low production cars. Get with Ed & let him tell you the story of how this all took place. Let us all know what YOU think. I'm happy with it......Joe

NoYenko · « **Reply #28 on:** November 13, 2011, 04:43:03 PM »

I received the re-pro 396 air shield from Ed Melberg, it is a really nice piece. I cant fit it to the car but I attached it to the core support and took some pictures.
x66 714 Thanks for your help.

NoYenko · « **Reply #29 on:** November 13, 2011, 04:44:38 PM »

Another picture

69Z28-RS · « **Reply #30 on:** November 13, 2011, 08:54:15 PM »

Quote from: jvb6648 on April 20, 2011, 03:19:16 AM

It has a part number but I couldn't tell you what it is. They were used on the Trans-Am race cars. I got that from a friend whose boss' brother worked on a Trans-Am team.

It's possible that these panels were *added* to certain small black T/A cars (by some race teams) for aerodynamic purposes....? to 'slick' up the bottom of the chassis?

BlackoutSteve · « **Reply #31 on:** December 01, 2011, 01:53:56 AM »

Quote from: NoYenko on November 13, 2011, 04:43:03 PM

I received the re-pro 396 air shield from Ed Melberg, it is a really nice piece. I cant fit it to the car but I attached it to the core support and took some pictures.
x66 714 Thanks for your help.

Is that somebody on this website? ..or, do you have any contact information and price on this item please?

x66 714 · « **Reply #32 on:** December 01, 2011, 02:04:26 AM »

BlackoutSteve

Those of you wishing to purchase a new reproduction can contact Ed at edmelberg@zoominternet.net. Leave your phone number & he will call you back. They are very nice. He has about 36 left. Regretably with the low demand & the expense of making these the cost is a little up there...Joe

BlackoutSteve · « **Reply #33 on:** December 01, 2011, 02:14:10 AM »

Thank you.

NoYenko · « **Reply #34 on:** December 01, 2011, 02:54:51 AM »

BlackoutSteve
I just revisited this post and looked back on the old posts where you wondered if they actually were installed at the factory. I worked at Jack Douglas Chevrolet back when these cars were 2 years old and don't remember the shields.
I found out by finding the holes on my core support and was going to weld them up before powder coating. Glad I didn't, curiocity prevailed this time. At the time I posted the picture I couldn't mount it to the car, but I looked for the holes in the subframe. They are there and one of the screws still has some of the plastic attached. I am sure most of these got torn up on parking curbs. The shield Ed makes looks really nice and matches any pictures I have seen.
George

BlackoutSteve · « **Reply #35 on:** December 01, 2011, 07:25:04 AM »

Unless your sheild was adapted from another car, you are the only person so far to have any evidence of having one..
Not at all saying that you aren't correct about your information, but where are all the others I wonder.

x66 714 · « **Reply #36 on:** December 01, 2011, 01:19:16 PM »

I've had my car for 29 years & those bolts & plastic that were spoke of still existed on my car also. Some of the other members of this group still had the piece in place on their cars. I looked for year to find this piece & I kept hounding the guy when I knen he was doing them. If you have a big block car w/air conditioning & it's still intact, i.e. original subframe & original core support, then most likely you'll find those holes. The car I have is an 08E 1969......Joe

BlackoutSteve · « **Reply #37 on:** January 15, 2012, 03:56:21 AM »

Thanks to this thread and those who have helped me, I have been in touch with Ed and purchased a shield from him. It's currently on the slow-boat to me here in Australia.. I look forward to receiving it soon. Thank you.

However, as I prepare for it's installation, I noted in the FAIM (C60-B4) that the screw #9420825 is not available through AMK..

Can somebody who has an original screw post some details and especially a picture -if possible, so I can order the closest available.

Hex size, flanged?, thread size, pitch, with self tapping flute?, UHL (under head length) and finish.

Going by P. Washer #9419275 (currently available from AMK as B-11266) and the 0.277-0.281" diameter holes to be drilled, I'm assuming a 5/16-18 with a tapping flute in an oil/phosphate finish.

Thanks again.

My68SS · « **Reply #38 on:** January 15, 2012, 07:33:26 PM »

Hi Steve, good to see you here!

Yes, I can also vouch for the Plastex stuff - brilliant, especially the moulding bar!! Used it to re-create a bunch of mounting tabs on a VL Calais.

z10kl · « **Reply #39 on:** January 16, 2012, 01:55:59 AM »

Any one have pics of the holes in the subframe/ I replaced my bent one with another.

NoYenko · « **Reply #40 on:** January 16, 2012, 08:38:35 PM »

Steve & z10kl, I can't seem to find the screws I took out of my subframe, I will find them & take pictures. I checked and all my holes are 3/8" X 16. If i remember they were same as front fender bolts,tapered end, with a recess in the center of the bolt head. I wish I took a picture of them before I pulled them, but I didn't know I was missing the air shield. Here is a very ugly picture of the subframe before disassembling. I pointed out the screws & holes.

Steve: I have to tell you I was amazed & entertained for many hours over the Christmas holiday at what you have posted on the Australian muscle car forum. What you have been able to do in what appears as a small moderately equipted garage is amazing and shows you are very talented. Anybody that likes Camaro builds needs to check the link under his name.
George

mark x22 · « **Reply #41 on:** January 16, 2012, 11:29:04 PM »

They are 5/16-18

z10kl · « **Reply #42 on:** January 17, 2012, 01:29:13 AM »

Great pic of the mounting holes.

NoYenko · « **Reply #43 on:** January 17, 2012, 04:06:25 AM »

Mark x22, you are correct 5/16" bolts. I have been looking at too many metrics or just can't see like I used to. Anyway I pulled out my subframe and shield to bolt it up.
The 2 bolts that go directly into the cross member are 5/16 with a .280" hole. But the other 4 holes only measure .250" so I don't know what screws go in there.The holes are not stripped, a 1/4" fastener is too small.
George

z10kl · « **Reply #44 on:** January 20, 2012, 03:32:48 AM »

Do you not have the bolts that came out of the holes?

JohnZ · « **Reply #45 on:** January 20, 2012, 05:10:06 PM »

Those were self-tapping sheet metal screws (like those used for gas and brake line clamps), not machine-thread screws; the holes in the subframe were just drilled, not tapped.

BlackoutSteve · « **Reply #46 on:** January 20, 2012, 11:02:00 PM »

This is confusing because the brake line clamp screws are a machined thread with a thread cutting flute.
Gas tank strap screws are a sheetmetal tapping thread with a point. The two are quite different.

Brake line screw 3958062 / B-10412 http://www.amkproducts.com/bulk3.asp?part=B%2D10415

This is the kind of screw I expected to see used here but, without the hex-flange because a separate washer is used. No where on these cars have I seen a hex-flange with a washer. Only hex with washer or hex-washer.

Gas tank strap screw 9420065 / B-12108 http://www.amkproducts.com/bulk3.asp?part=B%2D12108

BlackoutSteve · « **Reply #47 on:** January 22, 2012, 10:08:38 AM »

Sorry, I thought gas tank straps for some reason.. Forget that last B-12108 example..

Still, the threads on those fuel and brake clips were machined threads with the tapping flute and not regular self-tapping type.

NoYenko · « **Reply #48 on:** January 24, 2012, 03:29:34 AM »

Steve & Mark X22, I finally found the missing Air shield screw I was looking for. I thru it in with my front end sheet metal bolts. Any way I am sure this is it because when I took it out I remembered it was ground on one side like it hit the pavement or something. I am now questioning if the other holes I measured as .250" were filled in slightly from powder coating. I hate to put a 5/16" tap into it and open it up more but I have to find out what size bolt goes in there.I will let you know.
George

mark x22 · « **Reply #49 on:** January 24, 2012, 10:47:41 AM »

5/16-18 tap size is .257

big iron · « **Reply #50 on:** February 04, 2012, 06:34:07 PM »

Has the correct size screw configuration been determined?
There is something wrong with the 69 AIM C60 B4 UPC.
From an assembly standpoint I can not imagine a line worker having to stack 9 washers on screws and installing them while holding up the shield. It would be more efficient to have a washer and screw asm.
The screw hole piercings of .277/.281 would only work for a self tapping 5/16-24 or 32 if I am correct.
The only screw I think would work using the bolt and washer assumption is an over sized self tapping screw ( hex head wo/ washer) used on the front sway bar. Rick's shows them as SS-415 and are used when the screw holes are stripped. Bob

z10kl · « **Reply #51 on:** February 05, 2012, 04:29:39 PM »

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=220947515192&ssPageName=ADME:B:SS:MOTORS:1123
Here is an early LA built car that I noticed the holes for the shield on the underbody pics. Looks like 09B

9T4Z · « **Reply #52 on:** February 05, 2012, 05:21:27 PM »

Hijack: for all their 'knowledge' the Hendrick group advertised it as a September 69 build! Love to see the protect-0-plate

NoYenko · « **Reply #53 on:** February 05, 2012, 11:43:54 PM »

Mark,Steve & Big Iron, I pulled out the subframe, check the bolt holes for air shield they are all 5/16" X 18 in the sub frame & cross member.
Cleaned out the power coating with the tap I guess.
George

big iron · « **Reply #54 on:** February 06, 2012, 05:33:53 AM »

George,
Do the 5/16-18 bolts fit tight in the holes? If the holes where drilled to .277/.281 as indicated I would think the bolts would be loose.
What do the holes measure now?
Bob

BlackoutSteve · « **Reply #55 on:** February 08, 2012, 12:28:41 PM »

5/16-18 thread (0.3125") will tap into a ~0.280" no problem.

NoYenko · « **Reply #56 on:** February 12, 2012, 10:09:33 PM »

I was going threw some boxes today and came across the bag with my original AC shield bolts, cleaned them up & they are the same as my fuel line clip bolts #3958062.
These are the ones I took out because I bagged them. Wish I did that with all the bolts. Also they thread into the holes good not loose.
George

mark x22 · « **Reply #57 on:** February 12, 2012, 10:23:55 PM »

Can you take a picture of the end ?

NoYenko · « **Reply #58 on:** February 12, 2012, 11:42:25 PM »

Mark, Here you go. Sorry for the wrong picture 10 posts back. George

mark x22 · « **Reply #59 on:** February 12, 2012, 11:48:53 PM »

Thanks .

z10kl · « **Reply #60 on:** February 13, 2012, 09:35:16 PM »

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=280825594516&ssPageName=ADME:B:SS:MOTORS:1123
Here's a 10c early Norwood car that has the holes in the subframe.
Are there any known real BB AC cars with out the holes?

BlackoutSteve · « **Reply #61 on:** February 15, 2012, 10:26:18 AM »

Quote from: NoYenko on February 12, 2012, 11:42:25 PM

Mark, Here you go. Sorry for the wrong picture 10 posts back. George

Good stuff George.. Thank you for the detailed pics.

BlackoutSteve · « **Reply #62 on:** December 08, 2012, 10:22:51 PM »

I finally decided to fit the Air Shield that I purchased from Ed Melberg.
(This post is pretty-much a cut & paste from the forum that I am a regular on..)

The shield is shown here in the C60 (air/con) chapter of the Assembly Manual with all the dimensions for the mounting bolt holes. Lots of detail..

Both they and the shield are accurate and the shield fitted easily.

For drilling the front side of the radiator support, I had very little room for getting in a drill between the valance, let alone one with a drill bit in the chuck. So, I put a center-drill in my die grinder and it fitted and drilled easily.

These bolts from AMK (B-10415) are not THE correct bolts as the correct ones aren't available anymore, but they are very close and have the same self tapping flute in the thread like the correct ones. (-just like the 68-69 fuel and brake line clip bolts do.) They cut their own threads really well and just by using a ratcheting ring spanner to tap and install.

Done. Very neat and OE!

(..and no, I didn't need to cut an access hole in it for the remote oil filter like I thought I was going to. Phew!)

The whole idea of the shield is to maintain a low pressure area behind the radiator when the vehicle is at speed. This encourages the most amount of air to pass through the radiator and not allow air from under the valance that has "cheated" the radiator to fill the low pressure void.

Now. all I need is a hot day to see if it makes a difference.. The other day (without the shield) was a humid ~30°C (86°F), and the engine was cruising (@3500) with the temp at 190°-200°F with the A/C on high..
With OE thermostats being 195°F, that temp is hardly a concern, but I have a 170°F 'stat fitted at the moment and would like a little reserve up my sleeve for stinking hot days.

Otherwise, it rarely makes it to 180°F on cooler days with the A/C off, so the system works well.

Switching on the A/C typically adds 10°F.

NoYenko · « **Reply #63 on:** December 13, 2012, 01:39:24 AM »

Steve, Thanks for the follow up info, good to see it installed. George

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Author Topic: How to repair plastic/vinyl air dam (69 BB w/ AC) (Read 45963 times)

IZRSSS

IZRSSS

IZRSSS