NA6 Dash Restoration Project

This is a project that’s been in the back of my mind for a little while now. Ever since my CR.net buddy Cooper installed a 1600 dash (90-93) in his Roadster, I’ve been dreaming about this. The early dash just looks so… perfect. A great mix of 70s and 80s style. The NA8 dash (94-97) is absolutely decent and not-hideous, but that big passenger airbag takes a lot of style away. And all it seems to do is break windshields in the event of a collision or risk the lives of riders under 5 ft / 100 lbs.

And I got this fine dash for the outstanding price of zero dollars.

This dash belonged to my buddy Soren who owns a Spec Miata shop. It was sitting in a crashed out car (a 91 according to the VIN) with a broken windshield, exposed to the elements. It had a very thick layer of dirt and dust over top and was amazingly not-cracked underneath. A half hour under the 105* desert sun and I had it harvested and in the back of my Mazda3 hatchback. Hot sun motivates you to work quickly.

Did I mention free? Thank you for the deal, Soren!

I started my restoration from the back side and worked my way in. The first item to address was the defroster and eyeball vent duct work (duct works? ducts work?) tubes. I very carefully unscrewed them and massaged them free of the dash. They looked rough, but didn’t crack under my hands. A little soapy water followed by brake fluid followed by Meguiars Natural Shine had them back to factory fresh condition. They are extremely pliable and clean inside and out. I’m quite pleased.

Onto the frame…

Looks like my work is cut out for me. There’s far more rust on this dash frame than I’ve ever seen on any part of a New Mexico car. It is in need of some serious love and care. It needed more than I could provide on the spot that first night of disassembly.

I’ll come back to the frame in a moment.

The backside of the dashboard was also filthy. It got the same drill as the HVAC tubes – soap, brake fluid, Meguiars. And it polished up nicely! Only two small spots of breakage.

Both of these little tabs were pre-broken. The screws were holding the broken plastic in place, but the dash was just resting on top. I had to grab them with pliers in order to undo the screws. Probably the dash sat like this for years. I bet it rattled.

Plastic welder is great stuff, especially for hidden repairs like the back of the dash. You can repair the break and then gob up the epoxy around the broken part to create a repair stronger than the original part. It may not look so pretty, but no one will ever see it.

Later, this repair would be my downfall.

This is something I’ve read about, but have never had the chance to try – POR15. It’s a rust preventative / protection paint that just goes on right over top of rust. The guys on the Lotus forums love this stuff. Living in New Mexico, I rarely see even an OLD rusty car, let alone a newer one. (I still quantify my 15 year old Miata as “new”.) So, when the chance came to repair some rust, I was actually quite happy about it.

POR15 is a three step process. There’s a cleaner/degreaser, then a metal prep, then the actual paint itself. It really isn’t much more work than just painting a piece of metal, but you can’t just slop it on immediately. A quick google revealed this fact to be a bit of a bother for some car enthusiasts. I guess most just want to slop it on. Me? I like a long project.

This is just the starter kit that POR15 sells on their website. It’s more than enough to paint a rusty Miata dash and quite well priced.

Marine Clean is just a degreaser that you spray on and hose off. No rubbing or scrubbing necessary. It just frees surface rust and gets rid of any grease from hands, engines, etc. Notice how the frame is getting less rusty and my cardboard is getting more rusty.

YOU SHOULD WEAR GLOVES THROUGHOUT THE PROCESS.

None of these chemicals are extremely friendly to skin. My hands started to burn a few minutes into the degreasing. I immediately went inside to wash and apply rubber gloves.

Step 2 is called “Prep and Ready” which they apparently used to call “Metal Prep”. It’s another water-based solution that you spray on like the Marine Clean. This one needs to stay wet on the prep surface for 20 minutes. That means constantly walking around your part and spraying the dry areas. Again, NO SCRUBBING! No scrubbing was ever done to my dash frame. Hell, if the frame looked this good at the beginning, I probably wouldn’t have done the POR15 treatment.

After 20 minutes, hose off the Prep and Ready and let your part dry. You’ll begin to see the whitish coating of zinc oxide forming over the top. Apparently POR15 really likes to adhere to zinc oxide.

Seriously. Don’t trust your lungs to a little dust mask. Use a particle filtration mask like mine. It is worth having on hand for future projects. I’ve had this one for years and have changed filters a number of times. You can pick these up at any home improvement store.

You’ll forgive the lack of photos. I took quite a few. All of them were extremely boring. You just brush on the POR15, covering every nook and cranny. A minimum of 2 coats is needed. I was able to apply 3 coats to the entire frame with that tiny bottle of paint. I did the top side one evening and then flipped the frame over and did any parts I missed on the bottom the next evening. It hardens to a thick shell. It feels like the candy coating on an M&M.

Isn’t it a thing of beauty? Almost a shame to hide it under the 1600 dashboard.

A word to those using this as a POR15 guide and not as a dash restoration: you will need to top-coat this with some paint if your rusty part is to ever see daylight. POR15 doesn’t seem to like sun and will fade. Since mine is completely hidden, I don’t have to paint it.

Not bad, eh? I’m quite pleased. No more rust problems for this frame. Sharka should be able to proudly wear this dash for a long while.

Since I got the dash for free, I decided to not cheap out on these two consumables. Both like to break since they’re taken on and off more often than a whole dash is removed. The gauge hood (which is unique to the 1600 dash, by the way) cracks at the least provocation. It’s best to start off with a new one if you can afford it. I got this for $70 from Mazdaspeed Motorsports.

The tombstone (as the cluster is sometimes known) came from Japan. It’s ever so slightly different than the one we have in our USDM 90-93 dashboards. Those ones require an adapter to make a standard DIN radio fit in the opening. This JDM one does not. Just like the 97 tombstone in Sharka’s NA8 dash, a standard size radio slides right into place.

And so, I’m proud to present a completely restored 1600 Miata dashboard. Only 20 years young.

I shot this photo and was just beside myself. I was so pleased with my week of work. I couldn’t wait to drop the new dash into my beloved MX-5.

And then…

Yes. It cracked. The dash cracked right before my eyes. I rubbed my hands over the crack and could feel a high spot where the dash was being pushed up from underneath. The small bit of stress caused a crack. I flipped the dash forward and saw that the source of the stress was that Plastic Welded stud that I repaired earlier. My guess is that the whole dash had sagged a bit over the years due to those plastic tabs not being connected. Now that they were repaired, I created a stress area.

I cracked the dash with my own repair process.

I guess I’ll just have to repair the crack and then cover the whole dash with leather. Darn. And I guess there will have to be a blog post about it!