Project Boondoggle (or, so I went and bought a Z!)

[Matthew Abate]

Current options I'm considering:

• Cover the whole thing in Hexis vinyl
• Flock the whole thing
• Cover part in vinyl and flock the rest
• Texture and paint
• Full dash cover

At the moment, I think I like the first three options best, but I'll see what I think when I get more work done and reality hits me in the face.

I know a lot of people who have repaired their dashes leave the old plastic there, but it's old and very brittle and I don't think I could even get it back in the car without cracking again, let alone have it last for years in the future, so the plan was always to fiberglass it.  Considering that resin won't stick to plastic, the plastic is shot anyway, and that fiberglass will add some extra thickness in areas like the gauge pods it made sense to try to strip it off.  Even though the plastic on the lower sides was in good shape, I don't want to worry about any visual or texture mismatches, so it's easier for it all to come off.

I don't understand why fiberglass would be easier/better than the full dash covers I've seen for sale. Am I underestimating how difficult that job is or is it more that the covers themselves suck?

I'm asking mostly because I think I'm going to find myself in a situation where I need to do this too so I'm super curious what the reality of putting one of those on is.

[Captain Obvious]

Well good luck with the dash work. I'm going to have to do something about mine in the not too distant future too. Hoping you come up with something extraordinary.

[charliekwin]

5 hours ago, Matthew Abate said:

I don't understand why fiberglass would be easier/better than the full dash covers I've seen for sale. Am I underestimating how difficult that job is or is it more that the covers themselves suck?

 

The full dash cover isn't my preferred choice for primarily aesthetic reasons.  I've always thought the stock dash (along with the interior as a whole, really) was one of the things that betrayed the car's budget roots, so I want to try and dress it up a bit.

If you go with the full cover, then glassing the whole dash doesn't seem like it would be necessary but finding a way to reinforce the foam sections that have split would still probably be prudent.

I've heard some people have trouble getting the full cover to fit and removing the original skin might help with that.  The cover also doesn't extend all the way to the bottom of the dash, so you'd have to do some kind of blending for those parts

[charliekwin]

So far, so good.  Working first to fill the cracks and get the dash back into shape.  Like others, I've used the Great Stuff foam to fill the cracks.  I stuck some galvanized wire into the largest crack over the center gauge since it's thin and has nothing else behind it.  I put tape over the cracks thinking it might reduce the expansion and make it denser, but I don't think it made a difference or was worth the effort.

Side note: I'm a little surprised people have had good and/or long lasting results with the Great Stuff foam, given how much more compliant it is than the rest of the dash.

Trimmed off the excess and started with rough shaping, then continued sanding to try and level everything out.  Shot a light coat of black paint to try and highlight trouble spots.  It's looking pretty good: still some bumps to smooth out and I need to clean up the curve around the gauges.  I'd like to get the small gauge housings a bit closer to round as well, especially the clock.  Might be able to lay the first layer of glass by next weekend...if UPS can move fast.

[Matthew Abate]

Well, looks great so far!

I didn't realize the full covers we an actual COVER and not a replacement skin. If I had a million dollars if just send it of to be redone in cynic by professionals, but the quote I got back was $1,700. Can't remember who it was from. I just deleted it out of disgust.

Maybe I'll be following in your footsteps.


Sent from my iPhone using Tapatalk

[Namerow]

2 hours ago, charliekwin said:

I'm a little surprised people have had good and/or long lasting results with the Great Stuff foam, given how much more compliant it is than the rest of the dash.

I think that the compliancy of the Great Stuff foam may actually be a plus rather than a minus.   After 40+ years, the original foam has about zero compliancy left, so the stuff that goes in to fill the cracks has to be able to give as the dash surface grows and shrinks with radiant heat and changes in interior temperature.  For my repaired dash, my biggest fear is that the top, skim coat of 'Bumper Bite' repair compound won't have the same degree of compliancy as the foam underneath it.  The top coat is only bonded to the original vinyl skin by the width of that skin, and if the bond fails, a crack will emerge.   I beveled the OE vinyl skin so as to increase the width of the bond line, but that still only makes the bond along each seam about 3mm in width.  Only time and sunlight and temperature will tell the tale.  Since I completed the repair, my dash has been stored in the basement for 2 years, waiting to be re-installed in the car. 

[Captain Obvious]

Couple thoughts:

I saw a commercial the other day where the product in question was expanding foam. They were touting their foam as being better than the "bargain brand" because it had a finer texture and smaller, more consistent bubbles. Don't remember who it was, but there was something in the pitch about "gap control" and ended the commercial with a shot of the pitchman's teeth (with no gap between the two front teeth). If that's not enough description to find the stuff, let me know and I'll see if I can dig up who it was. It was one of the big name brands.

Also, I've heard people concerned that the fiberglass resin would eat the original foam. I've done no investigation into the concern, but you ought to make sure that's not the case before you slather large portions of your dash foam with the resin.

And third... I was in Horror Fright the other day and was looking at their "vacuum storage bags" which are these large bags where you put stuff to be packed away in a closet for long term storage and then suck out the air with your shop-vac. I was thinking to myself that there might be some application where you could substitute one of those bags for a vacuum table or resin form bags for something like.... recovering a dash maybe?

[charliekwin]

@Matthew Abate You're probably thinking of Just Dashes. They're actually about 30 minutes away from me.  They seem to do nice work, but the price (~$1800) is, well, a non-starter, to put it mildly.

@Captain Obvious I'm no expert on composites, but my limited understanding is that polyester resin might eat foam. It's also stronger and can withstand higher heat, but shrinks by about 10% when cured.  Epoxy resin shouldn't eat any urethane foams and only shrinks ~2% when cured, but won't be as strong or able to take high heats (150F+).  I'm using epoxy resin since those tradeoffs aren't a real concern, but yes, anyone who might be trying the same thing: test the resin first to make sure it doesn't dissolve the foam!

The spacebag approach might actually work!  Most of my prior fiberglass experience was on subwoofer enclosures and other audio parts and I didn't have a problem with bubbles.  The dash has a substrate that's staying in place, so vacuum forming shouldn't be necessary there.  I think vacuums are more useful if you're forming a part from a mold, like a center console.  And Harbor Freight's not that bad...I wouldn't be able to do some of the stuff I can without them!

 

[Captain Obvious]

Gotcha about the epoxy resin. I didn't catch that before and thought you were planning to use polyester.

And I found the foam commercial I was talking about. It's Loctite Titefoam. What caught my eye was the consistency and finer texture of the bubbles. It didn't have the large voids that form with some of the brands I've used:

https://www.youtube.com/watch?v=NB603veuD68

[charliekwin]

Fiberglass materials haven't arrived yet, and this weekend was shot with my kidlet's birthday party and the start of football season, so I only had time to deal with a minor diversion that I've had in the back of my mind for some time now: I finally swapped in the 280ZX vacuum tank.

Well, first I dealt with the nasty fusible link wiring that I inherited.  General laziness -- as usual -- got the better of me and while futzing around with the vacuum tank, one of the hot wires arced across one of the poor butt splices, so I took them all out, spliced and heat shrunk them properly.  I may still replace all this one day, but at least one fire/electrocution hazard is reduced, and I got my helpful semi-annual reminder to just take the extra 10 seconds and disconnect the battery before futzing around with anything electrical.

Anyway, the tank swap.  I picked up a vacuum tank from a junkyard for about $7 several months ago and always though it would be worth swapping in since the stock one is big and ugly and the hoses are rather convoluted (and those solenoids up there on the shock tower...eww).  It was a surprisingly simple affair: I reused the stock bracket (just lined with some rubber from an old bicycle inner tube) and the harness didn't even need to be extended (just crimped on some disconnect terminals).  Everything works as it should, though it did lead me to discover that the FICD has a stopper nut that mine -- surprise! -- is missing, so I'm on the hunt for an M10x.75 nut.  If there's any interest, I can do a proper write-up on the process...I feel like I owe this community something

[charliekwin]

I did a bit of final shaping on the top of the dash and tried, with maybe a little success to get the gauge pods into just a little better shape.  The curved section behind the small gauges had collapsed a bit over the years so I stuffed some crumpled aluminum foil under it to push it back into shape.  Everything looks good, so here goes nothing!

I exchanged some emails with the US Composites people and they didn't recommend epoxy resin for this project and suggested this stuff instead, which is usually used for surfboards.  Polyester resin eats polystyrene foam but is safe for urethane, and I did a test on a small part of the dash to confirm beforehand anyway.

Started on the top for the first layer of glass, and things went sideways pretty early on.  Composites experts, feel free to snicker under your breath now   This resin's thicker than the stuff I've used before and the fiberglass cloth wets out much differently than chopped mat.  It also doesn't conform to complex curves as well as I thought it would, AND the resin didn't impregnate the foam anywhere near as much as I expected (basically it didn't).  Because of all that, I had a fair amount of glass that I had to cut or sand away, but lesson learned: smaller sections moving forward.  

Well, lesson partly learned.  The curves on the gauges are a pain, the resin kicked early, and I didn't even get half of it covered.  More cutting and sanding.

And now, a new plan!  I figure what I really want the glass and resin for (aside from structure on the top) is to provide a suitable substrate for whatever covering I ultimately decide to go with.  With that in mind, I brushed a coat of resin over the uncovered parts of the dash.  I'm going to go back over that with some small strips of cloth instead of large pieces and hope that works a little better.

So the whole thing isn't exactly going to plan yet.  On a scale of 1 to Fiasco, this is a currently rating at Minor Annoyance.  Nothing's irrevocably borked by any means, but it is a bit more work than I expected.

[Captain Obvious]

Well you have just reaffirmed my reason behind why I have not attempted that maneuver. 

Good luck... We're all counting on you!