Saturday, July 12, 2008

Right Front Frame Rail Extension Patch

After cutting out the rust on my RH front frame rail, I ground around the cut, gave it a coat of Ospho, and then a coat of red oxide ZeroRust that I picked up at APS Paints for $57 a gallon. The Ospho converts the rust to iron phosphate and the ZeroRust sticks to that and prevents water and air from activating the rust in the future. I also painted the patch inside and out with DP74LF primer.

After another hour or so of adjusting and fitting the patch (funny how you think you got it just right and it still doesn't fit when it comes time to weld) I welded the seams on both sides and ground them flush.

As a side note, I discovered that pre-painting butt-welded patches like this is probably not a good idea since the paint all around the weld joints catches fire during welding and needs to be repainted afterwards anyway.

Finally, I repainted the entire work area again with a coat of ZeroRust and test fitted the new frame rail after surgically removing the remainder of the old rail. I left the lower seat reinforcement in place for this to help me align the new rail section.

I drilled 14 holes on each side and another 10 holes on the bottom and then plug welded the frame rail extension floor support to the rear portion of the front frame rail such that it contacted the floor reinforcement box and the tunnel crossmember.

Finally, I ground the plug welds down and will paint over the bare metal to complete the task.


  1. looks like there's a crossmember that your welding the end of the frame extension to!!!!
    my '65 stang doesn't have one

  2. Actually, what you're seeing is the edge of the lower seat reinforcement panel specific to convertibles. I'm really just using it as a reference for the extensions after which I cut it out and replaced it with new sheet metal.

  3. Are the tops of the frame rail extensions level with thew bottoms of the inner rockers?

  4. The tops of the frame rail extensions should be level with thew bottoms of the inner rockers, but mine were not. The after market inner rockers I bought were not a perfect match to the originals and did not allow for it. The bottom of my inner rockers were at least 1/4 inch lower.

  5. Awesome work you do! I bought -68 convertible also few weeks ago and I have all same work ahead. This is great way to learn what there are ahead. Thank you for good detailing work.

    1. Thanks Kari. I'm just happy that this blog has helped you. Take care and good luck with your 68!