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Discussion Starter · #1 ·
Ok...I am a little anal, but I think most of the Alfa Spider owners are actually. One of the air duct vents had a dent in it from a shoddy installation of an under dash radio, so I replaced the duct. While I was under there I noticed that one of the heater box door clips had some rust on it, and that there were only three there to begin with....one thing leads to another.

The heater is almost completely redone now, ,with the screws blasted and treated, and the clips painted.

In the process I noticed some surfact rust where the cowl duct hose passes through the fire wall. I would like to treat the rust before it spreads, and before I reassemble the heater box.

The question is, to do this I will need to remove some of the stock insulation from the firewall. As I examined the insulation it was very fragile, and brittle, and I do not think there is a chance in hell it will come out in a re-usable condition. For people that have stripped their bodies completely and repainted them, how do you replace this insulation?

I have a large roll of Dynamat and 1/8" open cell acoustic foam sheet that I think would do a very nice job, but it is far from original.

Should I take very special care and treat as small an area as possible, and remove as little of the insulation as possible, or is it acceptible to remove it completely and repalce with Dynamat or other more standard available insulations?

Thank you for your thoughts, Dave
 

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Re-Originals sells the correct insulation, and I like it much better than the Dynamat stuff...

Best regards,
 

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Discussion Starter · #4 ·
The dBLyte product looks very high quality and cost effective. Thank you for the lead.

I hope to start the disassembly process this weekend, but will have to work on it a few hours at a time, so the car will be out of commission for several weeks at a minimum.
 

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What did you ask???
 

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What did you ask???
It's right at the top of his first post, in bold:

To remove or not remove sound deadening in 1969 spider..

Anyway............

I don't think it's a bad thing to loose some of the original insulation. Take out as little as possible and try to re-install it but if it gets really torn up I also liked that dBLyte ossodiseppia linked to.

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It's right at the top of his first post, in bold:

To remove or not remove sound deadening in 1969 spider..

Anyway............

I don't think it's a bad thing to loose some of the original insulation. Take out as little as possible and try to re-install it but if it gets really torn up I also liked that dBLyte ossodiseppia linked to.

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Sorry, could you type bolder? I can't hear over all of this wind noise-hold on let me put the top up....:D
 

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Wind Noise

i agree that the wind noise can be a major concern when you're doing 135 MPH in your spider! Maybe you should roll up the side windows.
 

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i agree that the wind noise can be a major concern when you're doing 135 MPH in your spider! Maybe you should roll up the side windows.

That don't help any without any sound insulation!:eek:
 

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The original insulation can trap moisture resulting in hidden rust. On my car it was particularly bad on the parcel shelf, which looked fine until the insulation was removed.

If you have the time and inclination, I would remove the old stuff, and see what is under there. You can then paint and put down the insulation of your choice. I plan to use dynamat.

The old insulation can be difficult to remove, I used a heat gun and scraper. Some have recommended dry ice.

Marc
 

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Discussion Starter · #11 ·
I will begin the removal of the insulation this Saturday and will use the heat gun and scraper method for sure. I have also used 3M adhesive stripper that works very well for getting the old contact cement off. I am going to strip and paint the ****pit even though I can now see that most of what I thought was rust is actually old contact cement that has turned brown and is flaking off the fire wall.

Still thinking about the Dynamat solution as I have had prior experience with the the fabric insulations absorbing moisture and contributing to rust issues. I will keep the group posted on the final material decission and how the project goes.
 

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I will begin the removal of the insulation this Saturday and will use the heat gun and scraper method for sure. I have also used 3M adhesive stripper that works very well for getting the old contact cement off. I am going to strip and paint the ****pit even though I can now see that most of what I thought was rust is actually old contact cement that has turned brown and is flaking off the fire wall.

Still thinking about the Dynamat solution as I have had prior experience with the the fabric insulations absorbing moisture and contributing to rust issues. I will keep the group posted on the final material decission and how the project goes.
Dynomat does make a spray on sound insulator that resembles undercoating, but not tacky when dry-that would/should eleminate the rust issue, along with using their sheets IMO.
 

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The heater is almost completely redone now, ,with the screws blasted and treated, and the clips painted. Thank you for your thoughts, Dave
Cali, et al - how did you shimmy the heater box out. What else did you have to remove - besides all the attachments - to get it out? Which way did you slide it? Did you have to remove the fan box (underneath) first? Help? I'm doing this now (see thread). Thanks, Bruce
 

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Discussion Starter · #14 ·
Bruce;

You are correct the best way I found to remove the heater box was to first remove the fan box below. This is done by poping the four spring clips off using a long flat bladed screw driver. There are two clips on each side. Based on the design of the spring clip, and the orientation my clips were installed, it is easiest to pop off the top of the clip rather than the bottom.

Im my case I am removing the fan box only and do not need to remove the heat exchanger as it is pretty close to new.

Enjoy!

Pictures of the beginning of my project should be up Monday.
 

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Thanks and Follow-Up!

Cali, thanks.

I'll have to remount the box on the studs I guess as it's loose now. Will it be obvious which way the box then shimmy's out - to the side or to the front? The shift assembly is in front and the cowling drain hose and nipple seem to block it to the side. Perhaps with the ~6" of fan box off it will clear to the side.

I understand it will be a chore to get the clips back on, especially the back ones? My car sat for awhile and the valve insides look shabby (cover off now and diaphragm out; new one procured) so I am overhauling the whole enchilada. The engine radiator has been out. I'll take the heater element out for servicing also for the next "38", and refurbish the rest. Will take pics also.

Note Biba's restoration site on heater box restoration. Regards, Bruce

For others: Remove the lower fan box first via the four clips (unclip and gently pull the fan wire out wiht the lower fan box). Then remove the 4 upper retaining nuts (8mm socket with long extension and universal helps). The upper 2/3rds of the box just fell away easily and slid out the passenger side. If it's an old one, anticipate all the foam seals in he box to be crisp, the upper gasket to be shot and there to be some degree of rust. Anticipate a restoration of the box. IF it sat with antifreeze, anticipate replacement of the metal-type valve; at least the diaphragm.
 

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Discussion Starter · #16 ·
Bruce; You may not need to retightent the heater box bolts first. Also your intuition is correct with the removal. Push/pull the fan box down after removing the clips and slide it forward a few inches towards the shifter tower, then I slid mine towards the passenger side foot well. Please remember to disconnect the fan motor wires prior to moving the fan box very far.

Good luck.
 

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Question

Hey Cali, since I'm working on my heater box also, I note the same situation but no real rust bloom. But that insulation/soundproofing is pernicous. It has a tan/gold fiber with the box patterned vinyl material over the top that is brittle. Underneath that there is a much denser dark fiber and "tar" material bonded to the metal.

Are you stripping to the metal, both layers? I think I'll just let it be for now and only rework the heater box. No signs of rust on top or underneath.

What foam material did you use on your heater box rebuild? Did you find new grommets? (see here). Thanks, Bruce
 

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Insulation and Sondproofing Materials

Still thinking about the Dynamat solution as I have had prior experience with the the fabric insulations absorbing moisture and contributing to rust issues. I will keep the group posted on the final material decision and how the project goes.
Cali - Time for your update. I am at this point now. Doing a near-complete interior re-upholstery job (seats, rear drape, door panels, tunnel carpet, two mats). All is out.

What materials and methods did you end up using? There are four distinct materials I've found:
1) the thinner asphaltene soaked fibrous material on the floorboards, tunnel, and rear parcel shelf and lower bulkhead. I'm only taking this off the floorboards as the rest if nice looking with no signs or water intrusion (it's bear to get this off).
2) Over this, under the seats only, there is a fiber board material about 1/4" thick.
3) Then there is the tan thicker (~1/2") looser fibrous insulation material with the 1/8" checkered pattern vinyl-like covering on the inside of the firewall and tranny tunnel.
4) Lastly, there is a thin tarpaper over the rear quarters, over the top spring holes.

What have others used here?

Osso - I read your narrative but it only discussed one of the aforementioned materials replacements.

Thanks for the advice, Bruce

PS: I know DD, you can't hear this with the top down doing 135 . . . perhaps that makes the most sense of all. Prime and paint only . . .?
 

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For starters anyone who is trying to make their Alfa Spider quiet is peeing into the wind. Perhaps the S4's are relatively quiet, I don't know.

I've never liked Dynamat, now I hate it. A client's '69 Spider in the shop came with the stuff stuck everywhere, including in the recesses inside the trunk and hood lids. It either fell off, or had to be dynamited off. Apparently the client wanted the engine and the trunk contents not be bothered by loud sounds. The other client's Spider in the shop, a '58 750, doors were rusted out at the bottom. Once I removed the interior door panels it was easy to see why. The car had obviously been left outside (perhaps its entire life). One of the owners had stuck Dynamat inside the door panels, the sun loosened it, it fell off, and plugged up the two drain holes on both doors. Then it rained. Water over a foot deep had sat in each door for who knows how long. You have been warned.

I never remove solid undercoating under a car. I consider my work to be high quality street restorations and if a client or judge (note, I didn't say show car) cares to look under the car and find unevenness in the undercoating, I'm not in the least bit embarrassed. After the car is painted, but before it is color sanded, I go over all of the wheel wells and under the chassis with undercoating - primarily to cover the over (or would it be under?) spray.

I use the padding in the photo below, and am sorry but I don't know it's name. It is about 10 mm thick with a heavily stitched on silver mylar backing. I'll add that it is tough as nails trying to cut through when you're cutting out a piece in the middle - like for the seat runners. The silver goes down - next to the floorboard. I do believe one can cut down on the heat from both the engine and front muffler. I double layer this in the foot wells.

I only glue it down on just the very edges of the transmission and driveshaft tunnels. I don't do snaps, but use the sheet metal screws with the built in flanged washer to hold it in place, only where needed. My thinking is a person - if they were really foolish - let the interior get soaked, to be able to remove both the covering (rubber/carpet) and padding reasonably easily.

I've also made a pattern for the interior's sides behind the B-pillar and use roofing 'paper' and glue - similar to how they originally came from the factory.

Biba
 

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alternative insulation?

I used Dynamat myself and am pleased, but just the other day I ran into a guy who installs custom car stereos for a living. He is familiar with Dynamat but no longer uses it due to cost. He buys a product that looks and acts like Dynamat from a local roofing supply and uses it in exactly the same manor. It cost almost nothing. I believe he said 150 square feet was about $35. Too late for me but somebody ought to check this stuff out. Comes in sheets with the same peel off paper.
 
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