Gary Molitor's (1artworkz) Z31 image archive.
Frame Rebuild & Rust Correction.

POSTED 12-15-2005 & Up-dated 07-10-2009
If you find errors or would like to add information, you can
contact me using the email address at the bottom of this page.

12 gauge steel was used for all the bottom surfaces. 14 gauge was used for all the vertical surfaces. Patterns where made for cutting the steel parts. The parts where clamped and supported on the respective frame areas and tack welded. Parts where then shop MIG welded. Welds were smoothed with 80 grit 4.5" flapper disk. The inside of the replacement parts were painted with two part zinc chromate epoxy primer.

All the areas on the car where wire brushed 1.5" on either side of where welding would occur.

All upper edges were skip welded to the existing vertical frame surfaces. On a few occasions adjustments had to be made for proper fit.

Once the welding was complete, the new metal work was primed with the same rust inhibitive epoxy primer used on the inside. At this same time the under carriage was fully inspected for rust. Corrosion was found along most of the seams. These areas where wire brushed to bare metal and primed

In the spring of 2007, the frame voids were shot and filled with 15 lb./cf. structural ridged urethane foam. All jacking points on the frame have polished stainless steel pads affixed with Sikaflex 1A moisture cure urethane adhesive ... the same type of stuff used to glue windshields down. There are a total of twelve jack support points along the frame, three points along both the front and rear for floor jack and jack stands. On each frame rail there are three points for shop hydraulic lifts.

Bare areas of the underside were sprayed in the summer of 2008 with a white roofing elastomeric, a material very similar to the OEM undercoating. Once the  undercoating cured the whole underside and wheel wells were sprayed with one coat of metallic pewter two part epoxy followed with a clear coat of two part acrylic urethane.

Click a thumbnail for a larger image

Though not much rust was found in this area, the bottom surfaces were crushed in nearly an inch.
Crushed to the floorboard Bent in 50mph rear-ender Areas of work Patterns for parts
Front rail parts. Parts for rear frame member. Rear frame member. Frame members primed.
This area was almost rusted through and 3 bolts broke off in the disassembly This part was badly bent in the rear ender and contained rusted areas.
Front jack stand pad. Rear cross brace anchors, drilled and tapped. Garbage. Rear cross member.
Clamps and wood blocks were used to hold parts while being tack welded.
Parts clamped for fit Rust removal and welding. Primed with 2 part zinc chromate primer. Looking aft from the engine bay.
Reinforced with 1/8" steel plate and C section. In addition, pads for jack stands and floor jack placement were added.
Front cross member  from rear. Front cross member  from front. Rear differential cross member area, left side view. Looking forward, note the new tie down loops.
Engine bay frame rail with plugs to stop the. Front of engine bay frame rail with plugs. Larger holes were pluged with a sheet metal stop glued tyo the inside with Sikaflex 1A. Sheet metal stop with pop rivit handle.
caulk-gun-w-th.jpg (4218 bytes)
Sheet metal stop with Sikaflex 1A. 3 lb. foam volume compared to 15 lb. foam Box of empty cauling tubes for mixing the 2 part foam and injecting it in to the fram. Cauking gun with tube.
cualktools-1-w-th.jpg (5597 bytes)
Cauling tube with foam mixer. The 2 part foam was measured into the tubes by volune, mixed, caped then injected in to the frame voids. Inside the pasenger compartment a series of holes where drilled about 6" apart along the center of the frame rails. The foam would rise up and out of the holes. Once the foam finished raising, I would move to the next hole.
The foam found every open seam filling and oozing out out on to the drop cloth that protected the driveway. The Z31 was not very well sealed from the factory. No wonder those that live in areas where salt is used in the winter have such a problem with rust. More of the same. More of the same.
underbody-front-fw-th.jpg (6089 bytes)
Look forward from just under where the gas tank would be after the painting was completed. Looking back the here the gas tank would be. Front wheel well. Rear wheel well.
Rear showing detail of new tie-downs and SS jack stand pad. Transmission tunnel. Front reinforced frame rail with SS jack stand pad. Where we started.

 

Home ...

Emailnotice.gif (15302 bytes)

Gary's 300ZX home             The Art Of Gary Molitor

Site designed and executed by G.W. Molitor.
Copyright © 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005; 2005 Gary W. Molitor. All rights reserved
Send mail to the email address you find on the home page with questions or comments about this web site. Updated 09/1/2006.
Please note that the links offered here are not for commercial purpose but for your information only. This page is NOT complete!