Heat/sound barrier under carpets and mats in a 750

I guess you're saying that you want a very nice driver,close but not necessarily a completely correct car.If you have a spider,Alfa used a thick tar impregnated mat/material,something like felt only heavier,on the front floors and similar thick felt on the trans tunneI .They used Italian vinyl(Vipla)to cover the floors behind and under the seats.I don't think they used any insulation there,just glued the vinyl directly to the floor.So something to consider is if whatever type of insulation you decide to use,that it will accept glue if you are going to glue anything down,such as gluing carpet to the inner sills. I covered my entire floors with 3M sound deadening tar type,adhesive backed product(08840)appx.1/16" thick,and then used Thermozite on the front floors and tunnel over that.Thermozite is a "green product"made from plastic bottles into a single or double sided foil sound/heat barrier,appx.7/16" thick,so I liked that idea plus I had read that Thermozite had nearly the same sound and heat qualities as Dynamat as well as being much cheaper.All in all,made a difference AFA sound and feeling more solid,worth doing,noticeable,but no huge difference.No adhesives want to stick to the 3M stuff,it's not designed for that,although they claim that it can be painted.I tried most adhesives for gluing my rear floor vinyl to the 3M product with not so good results,might have to tear it all out and start over,again(just the rear floors and under the seats).The Thermozite did stick to the 3M product with spray adhesive and in some areas,60 second super glue.Please understand,none of this is a suggestion,just what I happen to be experimenting with and thought that you could use the information.Good luck,Phil

Phil,
Do you now have everything in your interior, and finished? Does the height of the floor under the mats and vinyl feel and look right to you with that thermosite down? Just placing my center carpet down for a test fit feels like it needs something like that under it to feel and look correct. It sits up a bit from the tunnel. It only had horsehair around the shifter and the tunnel area by the firewall originally. The floor vinyl is something I’m trying to get right now too.

If you notice, on most of the originality threads the vinyl has peeled away from its glued positions. Years of heat, climate and temperature changes is what I attribute that to, however my original vinyl clearly shows where the glue was applied to each piece, and the carpet areas with their screws. Only the edges of the vinyl were glued to floors’ sides. The back floor area’s short bracing wall had dried glue on it all. The small center piece was glued on first under the tire hold down bracket (as your one photo shows) then two vinyl pieces go over the back sides over those large holes. Those glued to the floor under the original tar & horsehair mat. My tar mats do not show any glue on them where they touch the floor vinyl. It looks like they placed the vinyl over those mats, then glued them up the sides of the tunnel and the sills under the carpet right to the paint.

Did you eventually glue your vinyl down to that thermosite? It looked to me that most of the vinyl had to be done in a certain order due to where the old glue was applied to painted areas. So, that’s how I am doing it. I am not happy with my glue quality for my vinyl to this point however, so I’m going slow. Like you said, ripping it all out and starting over doesn’t sound good. I sure do not want to rip the vinyl either.

I’m unsure if I’m sold on sticking insulation to floor areas due to possible moisture getting trapped under there. It’s not like you can lift it up easily to allow it to dry out from a flash rain event, or a heater core leak. That’s my biggest concern for adhesive-backed floor sound and heat deadening materials. A Spider is going to be loud no matter what, so is it worth it? Do you go ahead and apply it inside the doors and quarters too? Good questions for this thread. It does change the originality, albeit for a better and solid feel to the interior. Alfa only did some insulating on Giuliettas, right?...or was it just too early in time, or too expensive to do it thoroughly?

After talking with an old upholsterer, I am getting new glue for the back wall behind the seats. He said it’s not forgiving once it sticks, but it’s done once applied. Has anyone else found the correct order to applying vinyl, carpet and insulation that they can share?

I didn't put my carpet in permanently yet,but it is made so I was able to do a test fit.You'right Dave,the carpet doesn't want to lay flat and make compound curves too,so to get that front piece of tunnel carpet to lay flat(or a little better),I used a second 6" wide piece of Thermozite(I believe Alfa used a second thickness there too) from where the tunnels' sheet metal makes a step before meeting the firewall,basically between the shift tower and the step.Doing this flattens that step out.I ran it about half way down on either side of the tunnel.This evened out that front piece of carpet and helped it to lay better.It will still need to be screwed down at its bottom four corners and somewhere in between as well,but for me,I can't see this front piece laying down perfect.I suppose someone who knows what they're doing could use steam on it,but it'll be fine for me as is. I also used a double thickness of Thermozite on the front floors.I did glue these pieces to each other,one with the foil down(per instructions) and the second layer foil side up,don't ask me why.Doing this helped level the dip in the floor,which I like.The rubber mat lays better. I didn't know that there was any insulation,horsehair/tarmat etc.on the rear floors,I would've probably used the Thermozite there too,and "not" glued the vinyl completely down to any insulation,only around the perimeter.(Smart move to get glue from an upholstery shop). I did not glue anything to the Thermozite.Again,I'm not suggesting anybody use Thermozite,I used it only because it is a green product,supposedly equal to other like products,and they claim it will not hold moisture or mold? AFA protecting the floors from moisture and eventually rust,bedliner and/or products like Lizardskin are being sprayed on all inner sheet metal.Something like this would have to help with noise as well.Since we've already hijacked this thread,I'll show how I got around a minor pita while doing the vinyl for the spare tire bracket.I made a small insert out of plywood to have something to glue to,making this area easier to do and in my opinion,more pleasing to look at,if anyone ever does.Another tip is when gluing the vinyl to the rest of the crossmember,stay away from those large holes with glue,otherwise your more likely to see the impressions of those holes after the vinyl is in place.I'd say no closer than 1/2" from those holes with glue.

Phil,

This is exactly what I have been needing to see; a pictoral presentation of an involved restoration process.

I read something recently about gluing a semi-rigid sheeting over the holes in the cross brace to prevent them from showing once the vinyl has been applied. What are your thoughts on that technique?

Your firewall mat is the best looking one I have seen. If you don't mind my asking, where did you buy it and is it covering a Thermozite underpadding?

Again, thanks for the discussion and photos; a visual learner's dream come true!

And I can't imagine that anyone would think this thread has been hijacked. If anything, you've held a clinic on the subject!

Ray

Raimondo,Thanks for the kind words,but I'm just learning as I go just like many of us,including you.Mistakes will be made and experience is still the best teacher. Using thin plastic over those holes is not a bad idea,but many spiders have been done beautifully without it.I'd guess that the plastic would have to be blended or sanded wherever you end it,such as along the top or face of the crossmember,wherever you decided to end it.A grain of rice under the Italian vinyl(vipla)will just about show up,so do a test run on some scrap to see if the transition from your thin plastic to a hard surface is too obvious under the vinyl,maybe not??.Also try to avoid stretching the vinyl whenever possible. I made my firewall mat using Vipla and MD insulation(common yellow fiberglass heating duct stuff) using my old mat for the pattern.I think Thermozite would be too stiff.I was lucky in that I was able to reuse my original snaps and carpet grommets.Probably cost me under $100.00,but took a decent amount of time.I don't know your situation,but if it doesn't hurt $$,I'd buy one,it gets covered anyway.

Ray,
You can see in Phil’s pics those thin sewn areas we discussed earlier. I promise I’ll get those patterns out to you after I get my new vinyl completely in. The originals were not perfectly trimmed around the seat risers. Many of us here are way more picky! I’m still using the pieces to make sure my left and right side are correct-fitting. I had to work around the holes for the seat belt eye bolts, which I left the way I received them. Getting the insulation pad, shock access covers, and belts installed were all satisfying after looking at them in boxes for years.

Ray,If you're set on making your own firewall mat,I'm pretty sure I still have my original firewall vinyl I can send you to copy.Although some of it was missing,it was still usable as a pattern.When I first got my car,I threw some stuff away too,live and learn.OTOH,now I don't throw anything away and have a box of rotten,petrified,smelly,incomplete pieces of useless seat foam sitting in my basement,there must be a line to draw somewhere?. Notice in Dave's photos he has bedliner type material on his floors,good idea,and also notice that his crossmember holes don't show.It can be done w/o plastic.Here are some pictures of the floor vinyl around the seat risers.I made neat folds for a finished look around the front seat risers,totally unnecessary.Pic. 2 shows the rear seat support without folding it and actually looks better.These things are hardly visible anyway and Alfa didn't bother with such details either.Also notice in the first picture how the 3M insulations' diamond pattern is showing through the vinyl,as well as not sticking very well.Just sayin' how everything will show throught the vinyl.In this area,not so important,and the sill carpet comes down to the seat supports/towers covering some of this vinyl,but you do want the floor vinyl behind the seats to be nice and smooth.

alphil said:

What is this sturdy material you used,I might do my rear floor vinyl over?

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I used this stuff. It’s a trial material for me as I install the interior, so I can’t vouch for it yet. It’s from Textile Specialties in Forest City, NC. It’s fairly strong and I don’t think it will retain moisture. It’s about the same thickness as my old tar/horse hair floor pieces. I put it over a thin layer of smooth sound deadening, then vinyl over it. I may regret the sound deadening for originality purposes, but there seems to be a lot of people using sound deadening that swear by it. I just want mine to look like it’s stock, but try to make sure it’s better in the hidden areas because of something I’ve done, instead of the opposite.