DIY Soundproofing/ Vibration damping / Heat management for Mazda Miata

[— Agent☣Orange —]

I had my top replaced a couple of years ago and it came with a new rain rail. They did say that the drains were completely blocked. Perhaps that was a contributing factor as well. The original install of the roll bar was over 10 years ago. It was at one of the first tech sessions that the club had.

Plugged drains would most likely lead to a moist floor but a leaky rain rail will cause water in the trunk and parcel shelf rust as well as the main floor.

So, setting the cancer aside, what are your plans for insulation?

Last year, I helped a friend line his wife's mx5 with "Reflectix" on the floor and transmission tunnel. The material is like a thick, metallic bubble wrap. It cut down on the internal cabin temps by quite a bit, but didn't do much for noise. My other concern with it is that if the cabin gets wet the plastic might not be breathable enough to dry properly.

Reflectix is a great heat barrier but a poor noise and moisture barrier. I lay sound damper to seal out moisture before any Reflectix.

Reflectix is good stuff! YellowYata endorses it! I'll be using it as well in my cabin.

Only in areas where it can be used as designed such as blocking heat from the tranny tunnel. It's worthless on the parcel shelf.

I use multiple layers of different materials for different functions. Here on the tranny tunnel, I used a base layer of Rattletrap (like Dynamat) to moisture proof the tunnel and stop resonation (sound damping) but then added two layers of duct insulation to address the primary problem, heat. Then one last layer of Reflectix for heat reduction and to stop the burning-calf syndrome. Now it gets barely warm to the touch, even on long drives plus the cabin stays cooler and the AC less overworked.

I'm no metallurgist but just wondering if maybe the two metals contacting each other combined with rain helped speed up the rust process? Maybe put some thin rubber gasket between the plates when you go to re-install all of these parts?

. I think it's just a combination of time and iron content, maybe throw in a humid environment a little trapped moisture. Any time you drill holes for roll bars and frame rails, you're stripping away the rust-prevention. A rubber gasket would be cool but might trap moisture since the two surfaces aren't perfectly flat.

I'd just use a lot of spray-on with newly drilled areas along with silicone.. That roll bar and tunnel are going to need some thorough rust removal and hopefully the tunnel metal is okay. The roll bar can just be cleaned and powder coated. I'm wondering if that whole area coud benefit from some layers of spray-on PlastiDip. I've always wanted to experiment with that stuff for rust proofing.

[Radiohead]

I'm no metallurgist but just wondering if maybe the two metals contacting each other combined with rain helped speed up the rust process?

Maybe put some thin rubber gasket between the plates when you go to re-install all of these parts?

Very possible. Perhaps some type of galvanic reaction. I'll have the bar out shortly. Then it's off to the welder for the final diagnosis.
And oh yeah, it gets a gasket on both sides the second time around

[minuteman048]

She has always been parked under the carport. Thanks! Im glad i decided to do this or i never would have known what going on back there with the roll bar. After reading thru your thread I had a pretty good idea on how to proceed. I will say this though, I hope my completed job looks half as good as yours! You were meticulous and it shows in all your pics!

I get 2 weeks off between Christmas and New Years so I was able to take my time and work in comfortable temperatures. It's easier to do a big job when you are not rushed and working in comfortable conditions (not summer heat). Yata did his before I did mine and he was my inspiration. I used a small wooden roller you would use for doing wall paper to get the material to match the contures of the floor pan. It came with the Fatmat roll which I used for the job. Good luck.

[— Agent☣Orange —]

I admired MM's work too. Looks like it came from the factory that way. If you don't do it for a living, it's a major pain to cut rolls of damper and fit custom shaped pieces so they all look seamless.

You can't use your good scissors because you'll get sticky tar all over them and crawling in and out of the Miata with the top up so you can reach the parcel shelf is an unenviable chore not to mention having to press every square inch. It's one thing to look at pictures but anyone who has done this sure has my respect.

That's why I prefer the "since you're already in there" approach to this project. If you're replacing your top, lay down some stuff since you're already in there. If you're replacing your floor carpet, lay down some stuff since you're already in there.

[Radiohead]

I have removed all the nuts and bolts that anchor the roll bar. Since I'm by myself, I was unable to lift it out. Hopefully, I may have someone tonight to help me. I'll post up pics showing the water damage to the bar and base when it's out.

[Radiohead]

Roll bar is out and the sheet metal under the mounting tab looks good! Just need to do some light sanding and apply some rust inhibitor. The roll bar mounting plate has plenty of metal left so its salvageable. Lots of sanding and more rust inhibitor should take care of it.

[— Agent☣Orange —]

That's great! Now get that rust out. BTW, when was the last time you pulled up the main carpet and checked for moisture?

[Radiohead]

That's great! Now get that rust out. BTW, when was the last time you pulled up the main carpet and checked for moisture?

That would be NEVER lol. That's next. BTW, the drain holes on both sides of the tub are jammed full of leaves and the like. Guess what I will no longer be neglecting! Any suggestions on how to clear the drains? I have one of those clothes dryer pipe brush looking things. I'm going to give that a whirl.

[— Agent☣Orange —]

You HAVE to check your floorboards once in a while for moisture/rust. The carpet is waterproof but water gets in beneath it because of clogged drains. It gets soaked up by the batting and since the carpet is non-porous, water gets trapped beneath it forever. It can't evaporate; just sits there like a wet towel creating a perfect condition for rust. Worst case scenario.

This is not a major operation. Just pull up the plastic door sills, lift up the edge of the carpet and stick your hand in and feel around for moisture. If you feel anything wet, yank out the front kick panels and seats and really lift the carpet for a thorough look/dry out.

You can clean your drains with any long object but do it somewhat gently so you don't disconnect the tube. If you've never done it, you might see all sorts of crud dump out in front of the rear tires.

[Pfunk]

Soundproofing and reducing cabin heat are going to happen with a seam-weld and repaint sooner than later for my car but I need to take a small break after what I had done with the motor and transmission... *sigh* the list is never-ending.

[Radiohead]

You HAVE to check your floorboards once in a while for moisture/rust. The carpet is waterproof but water gets in beneath it because of clogged drains. It gets soaked up by the batting and since the carpet is non-porous, water gets trapped beneath it forever. It can't evaporate; just sits there like a wet towel creating a perfect condition for rust. Worst case scenario.

You can clean your drains with any long object but do it somewhat gently so you don't disconnect the tube. If you've never done it, you might see all sorts of crud dump out in front of the rear tires.

Since I'm pulling the seats and carpeting out to do this little project, I'll be able to inspect the entire cabin. I'm hoping to not see anything (best case scenario) and preparing for the worst! Hopefully what I find will be somewhere between the two.

I'll be extra careful with the drains. Judging by what I felt at the top, they may be considerably clogged. I'll start out with the shop vac and an attachment I made from an old radiator hose for reaching into tight spaces. After that, I'll work a flexible piece of cable in there until its cleared. I just have to incorporate drain inspection into my normal maintenance routine going forward.

[Johnnie]

Since I'm pulling the seats and carpeting out to do this little project, I'll be able to inspect the entire cabin. I'm hoping to not see anything (best case scenario) and preparing for the worst! Hopefully what I find will be somewhere between the two.

I'll be extra careful with the drains. Judging by what I felt at the top, they may be considerably clogged. I'll start out with the shop vac and an attachment I made from an old radiator hose for reaching into tight spaces. After that, I'll work a flexible piece of cable in there until its cleared. I just have to incorporate drain inspection into my normal maintenance routine going forward.

I bought a trombone brush just for cleaning the top drains-- long plastic coated cable with a little brush at each end. Snake it down the drain until you see it pop out underneath the car and then pull it through. Repeat until no more crud comes out with it.

[Radiohead]

Now that sounds neat. Where can I pick one up? There's a Paragon Music up the street.

[Johnnie]

I got mine at Sam Ash on McMullen Booth.

[Radiohead]

Cool,
Thnx