Liquids seal is better

3m urethane or 3m weatherstrip adhesive

Some of this is obsessive. I doubt your car will ever see enough rain to be an issue. Even parked outside all of these cars are 50 years old and rust at the emblems is not the issue.

No offense intended...

13 minutes ago, Patcon said:

Liquids seal is better

3m urethane or 3m weatherstrip adhesive

Some of this is obsessive. I doubt your car will ever see enough rain to be an issue. Even parked outside all of these cars are 50 years old and rust at the emblems is not the issue.

No offense intended...

Ha!  Some of it is obsessive - no doubt.  I appreciate your input. 

My first car was a 4-door 510.  Being just 16, it was a prized possession, and I used to wash it about every week.  Water got into that car and under the floor mats something fierce.  One day, to trace the sources of the leaks, I set up a hose so that water showered down heavily on the car.  After about 20 minutes, I got inside and looked to see how water was getting in (I had removed the kick panels and floor mats, etc.).  I was quite surprised to see that a main point of ingress was one of the bolts clamping the LF door hinge to the car.  A steady stream of water was wicking along the bolt threads from outside to inside the car and running downward from there, collecting into a pool on the floor.  Interestingly, though I thought the windshield seal might be leaking, it was not.  I also recall finding that if I pointed a spray of water from the hose at the c-pillar vents, water would fly in... it would get directed upwards by the internal part of the vent, and then drop down onto the trunk floor, where gravity would direct it to the lowest area under the rear seat bottom.  

When I restored my first 240z in 1993, I had to reconstruct the dog leg areas of the car with new metal.  A few weeks after I got the car painted I was shocked, and upset to find standing water in the dog legs of that car.  I couldn't figure out how it was getting in and just drilled a hole in the bottom of the dog leg area so the water that was  collecting there would drain out.

For this car, I'd like to know that when I wash it, or if I get caught in a thunderstorm with it, no water will enter through the emblem holes and dribble down into the dog legs, or down into the back edge of the rear hatch.  Newer cars tend to utilize water proof solutions like this BMW clip, which utilizes a rubber plug, of sorts:

 

Given my previous experiences, I figure I might as well address these known water entry points.

 

 

 

 

I took a break from working on parts/hardware prep this weekend and worked on a few other projects.  My plan is to finish up with that prep and send everything off for plating in a week or two.  When I get everything back, I have some sheet metal that needs to be bolted to the car a final time before commencing on the last round of priming and blocking.  Some areas of panels "move" significantly when they are bolted in place.  This is true of the fenders, and especially the cowl panel... which brings me to a cool little project I did this weekend. 

From the factory, Nissan installed some closed cell foam under the flat corner areas of the cowl panel of my car.  It wasn't there on very early cars, but was a production change.  This foam sheet is sandwiched between the unibody and the cowl panel eliminating an "air gap" which can cause the panel to vibrate.   

I am quite pleased to say that I have found replacement foam that I honestly can't tell apart from the original, other than it is new of course!  It looks the same, feels the same, and has the same density (to the best I can feel). I made up some replacement pieces today: 

Old for first pic... then old on top of the new sheet for the second pic... and pic showing thickness of old stacked on new:

     

It's great when something goes so well.  I made some extras.  If anyone is interested in a set, let me know.  Be aware that if you've done final body work or paint on your cowl panel without your foam pads, installation of these will likely move your panel somewhat.  Best to utilize them during final bodywork prep.  

  

 

When I get the hardware back from being re-plated, I will be able to bolt on the cowl panel with these new foam supports which will positively locate the flat areas of the panel so that I can proceed with the final sanding required to get it prepared for paint.  

Edited August 16, 20213 yr by inline6

3 hours ago, inline6 said:

I am quite please to say that I have found replacement foam

I guess your cowl was rust free but that foam was the cause of thousands of rusted out cowls, water got trapped between the cowl and the foam and it couldn't evaporate.  I put 3 little blobs of RTV where the foam used to be so the cowl is still supported but there's no place for water to hide.

On 8/15/2021 at 10:02 PM, grannyknot said:

I guess your cowl was rust free but that foam was the cause of thousands of rusted out cowls, water got trapped between the cowl and the foam and it couldn't evaporate.  I put 3 little blobs of RTV where the foam used to be so the cowl is still supported but there's no place for water to hide.

Ah.  Yeah, I can see that.  I like your solution.  I will take some extra care with gluing the pads in place and will apply sealant around the edges of the foam to keep water from getting in under them.

Edited August 17, 20213 yr by inline6

Decided to switch over to installing more "tar mat".  Where I left off was with the passenger compartment floor surfaces finished with both a layer of Second Skin mat and a layer of factory mat cut and installed.  I had only installed the Second Skin on the tunnel.  So, cut and installed the factory mat on top of that on the driveshaft tunnel.  

  

    

  

  

  

    

    

 

I didn't take as many pictures showing step by step progress, as this is a repeat of sorts of similar prior work.  A bit of finishing work is needed for the front tunnel piece where it meets the fire wall.  After that, all that is left is the rear hatch area.

 

Edited August 24, 20213 yr by inline6

Nice work. Looks great. 

Thanks!  This past weekend I started on the hatch floor area.  In looking at the templates you created, I realized that those are for a series 1 car.  So, they differ a bit from my series 2.  Once again I had to do some investigative work, looking closely at clues on my car to decipher where the original sound deadening mat was.  My car still had the mat present behind the shock tower, but the portion between and in front of the shock towers had been removed by a prior owner.

 

After careful removal of some kind of black coating, likely applied by this same owner, I was able to see where the original mat use to be.  The original silver paint outlines where it was.  I started applying tape so I could make a template:

    

 

The outline was taped off.  Then masking paper was used to fill in the outline.  

    

    

 

Next, I removed the remainder of the factory sound deadening.  Then, I used the template to cut the Second Skin mats.  The adhesive backing is still in place on each mat.  Fitment was done first with each mat held into position by using masking tape.  Next, I will properly strip the hatch floor so it is prepped for a coat of epoxy primer.  

    

        

I picked back up on the work in the rear hatch area.  I removed the remaining portion of the old sound deadening mat and found a bit of rust under it. 

    

I tried to remove it with a wire brush on a 4.5" grinder, and some hand sanding, but when you have the ability to strip with a "sand" blaster, everything else feels inferior when considering the result.  Unfortunately, sand gets everywhere, so time for clean-up becomes a major factory.  I should have stripped the rear hatch floor at the same time that I did the passenger compartment floor.  I would have saved a lot of time in the long run.

After sand blasting, I sprayed epoxy primer to the bare metal:

    

    

I then applied the Second Skin pieces which I fabricated last weekend.  The adhesive on this butyl rubber sound dampening is very strong.  You have to be very careful when it first contacts the car to have it positioned correctly.  After those were all in place, I used the backing paper from them as templates for the factory type of insulation.  These templates are more accurate than my initial paper templates. 

  

When cutting the factory mat, I made the cutline about 3/32" outside the template edge.  This makes the factory type mat a touch bigger and allows the edges to radius over/around the second skin mat for a slightly better look in my opinion.  

    

    

 

Finally, the effort to replicate the factory sound deadening mat is nearly complete, just a bit more to do at the firewall.  I will be applying a 3M flexible seam sealer to all of the edges so that water can't get under it anywhere in the future.   I am pleased with how it turned out.  It is difficult, in my opinion, to distinguish it from the factory applied original, however it has the benefits of more modern technology - butyl rubber, strong adhesive, metal foil for heat shielding. The factory type stuff on top which looks nicer though and conforms to compound curves more easily.  The resulting sound deadening is noticeably better.  

 

Edited September 12, 20213 yr by inline6

While I was doing the above work, I snapped these pictures which clearly show evidence of how water came into the car from the quarter panel vents.   The hole in the quarter panel has this "U" shaped plate behind it which has some sealer not very well applied to the edges where it meets the inside surface of the quarter panel:

 

In the bottom right hand portion of this photo, you can see where water ran down from the vent to the junction of the inner fender wheel well and the quarter panel. The car is at 90 degrees on the rotisserie with the left side of the car facing the floor:

 

It seems wise to apply more seam sealer to the "U" shaped piece to make sure it doesn't let water in along its edges.  That said, the top of it is open.  So, it is not a good idea to hit that vent with a stream from a hose.  🙂

I will be be applying some spray on sound deadener to the inside surfaces of the quarter panel.  However, before that, I will be prepping and addressing any suspicious areas of factory sealant to ensure no water can get in to cause trouble.

*edit - I also noticed today that the bottom of the three holes that hold on the Z emblem is located below the bottom of the "U" plate, whereas the two others are contained within it.  So, the bottom hole is more problematic for letting water in for what that is worth. 

 

Edited September 18, 20213 yr by inline6

Last weekend, I directed my efforts finishing up the sound deadening mats and at the car interior surfaces.  The glue sprayed onto various areas to secure the vinyl trim is quite difficult to remove.  After trial and error of various methods, I settled in mostly on using a very stiff metal brush.  It seamed to pull the adhesive off the best while least effecting the existing painted finish.  Adhesive remover is ok, but more messy and it can prolong the process because the adhesive gets sticky again and smears to a degree.  Wiping a cloth with adhesive remover just back and forth briefly on the adhesive and then letting it evaporate for a bit seamed to soften up the adhesive a proper amount to aid with quicker removal with the stiff wire brush.  Soaking the adhesive doesn't help as it turns gooey and wants to keep sticking as you are brushing it.  And it can get clogged in the brush and smear to other locations.  Examples of old adhesive:

  

 

My goal for the interior prior to getting the car painted is to prep the surfaces by removing all of the adhesive and putting some tooth on the old paint so primer and paint can be applied achieving a clean, "factory applied" paint finish. The original paint is thin inside the passenger compartment and it is easily broken through to the oxide type primer which was applied at the factory.

    

 

I find the black paint applied by hand with a brush in this circle interesting.  The purpose on my car is so the silver does not show through the pattern of vent holes in the trim finisher that goes inside along the rear quarter panel.  The presence of runs and drips is interesting to me.  

  

 

I also applied seam sealer to all the edges of the sound dampening mats.  This way, water will not be able to get under them in the future.  One thing to note is that impacts to the floor can cause the original material to pull loose from the floor as well was crack.  This creates an opening for water.  If your floors and sound deadening are still not rusted out, you should have a look and address issues via sealant to attempt to keep them that way.

    

    

 

I see  have some spots where I missed application of the sealer, so I will need to touch those up: 

 

Hand sanding the tire well is a time consuming exercise.  Power tools don't fit in here well and I didn't sandblast it.  So, hand prep it is.

 

 

 

I've spent a lot of hours scrubbing, scraping, sanding, etc. to remove all of the glue from the inside panels of the car.  Getting it off shock towers, inner rocker panels, roof, hatch openings, luggage riser, firewall, and inside the tool compartments was a job.  I've still got more prep to do before the inside of the car will be ready for paint, but after about 4 Saturdays, I called it 'good enough' to get a layer of epoxy on top of the newly installed sound deadening mats in the passenger compartment.  The hatch area will get the same treatment with epoxy soon.

A video follows, but here are some still shots as well:

    

 

    

 

    

 

    

 

 

 

Edited October 27, 20213 yr by inline6