Original Parts with an Original Fit!

Posts in category Restoration Information

Mig Welding Techniques

Using Mig welders can be rewarding, as they are user friendly and work very well when needing to complete a body panel replacement on a Classic Mustang.  A wire feed welder with argon gas yields a much smoother weld than welding with flux core wire.  Here are some tips for perfecting your Mig welding skills:

  1. Clean the surface area.  Do your best to grind, sand or media blast the areas that will be welded.  The cleaner the surface, the smoother the welding will turn out.  And, the more time you will save when grinding and cleaning up excess welds after welding.
  2. When holding the welding tip, weld in a direction which pushes forward, rather than pulling the tip toward you.  Welding forward, in a forward motion, ensures that the gas is able to clear the area to be welded of contaminates.  This creates a cleaner weld.  Pulling the welding tip toward you makes you pull in the opposite direction that the gas is exiting the tip, defeating the purpose of the gas.  This technique is difficult to get used to, as it feels more natural to pull toward yourself, but the results are worth the extra effort to learn the correct technique.
  3. Welds should be smooth and flat.  If welds are too high or too thick, they will need to be ground down, which is unnecessary work.  If your welds are turning out too high, your wire speed may be a little high.  Adjust the speed down to a lower setting.
  4. Welds should not burn through the metal.  If they are, your voltage may be set too high.  Adjust it as necessary.
  5. Practice on a scrap piece of metal to discover the settings that will work best and familiarize yourself with the proper settings.

For more tips on wire feed welding, see our Body Panel Patch Welding Tip post.

Body Panel Patch Welding Tip

How do you weld a seam that is almost invisible on your body panel? Take some time to make your replacement patch a perfect fit.  Ideally, there should only be a 1/32″ (or less) gap between the patch and the body panel.  Place the welding tip wire through the gap and tack-weld the patch in place (put a couple of small spots of weld here and there).  This holds the patch in the correct position.   Next, begin welding a small portion at a time (1/2″ to 1″ usually works the best).  Be careful not to weld too much at once, as this would warp the body panel.

Once the welding is complete, carefully grind the welds flush with the existing body panel.  Further welding may be required to fill the areas that were missed.  Wire feed welding is a good weld for beginners to try.  Try practicing on a piece of scrap body panel before attempting to weld your body panel.

Tip:  when purchasing a wire feed welder, make sure it’s a name brand and purchase the welder set-up that uses the argon gas rather than flux core wire.  Gas aided welding is much smoother and user-friendly.  It’s a little more costly, but well worth the investment.

Unibody Panel Replacement

Unibody panels need to be replaced when they are rusted or damaged.  After spot weld drilling and panel cutting is complete, it is time to begin fitting the replacement panel.  This guide will apply to most panel replacements, including roof skins, rear quarter panels or patches, floor pans, cowling vent, taillight panel and trunk floor.  It will take you through the steps of replacing a panel.

Tools Needed

  • Hammer
  • Dolly (a variable shaped iron straightening tool)
  • Drill or Air Punch
  • Clamps and Vice Grips
  • Shears
  • Sheet Metal Screws
  • Impact Driver
  • Welder
  • Grinder

Body Panel Replacement Process

  1. Drill all spot welds and remove the old panel.  For further information on this step, please see our guides on Locating Spot Welds for a Unibody Panel Replacement and Drilling Spot Welds for a Unibody Panel Replacement.
  2. Use the hammer and dolly to insure all flanges are flat and free of distortion.  This can be done by placing the dolly on one side of the flange and hitting it with the hammer from the other side of the flange.  This will straighten the flange.
  3. Using a grinder, grind all excess spot weld bits and pieces smooth.
  4. Next, fit the replacement panel in place.  Some panels require slight trimming or slight reshaping, depending on the reproduction panel.  This is done with shears and/or grinder for trimming and hammer and dolly for reshaping.  NOS parts fit the best with minimal reshaping, but are not readily available.
  5. Once the panel has been nipped and tucked and fits reasonably well, clamp it into place using vice grips, C-clamps or sheet metal screws.  Helpful tip:  if you are installing sheet metal screws to hold the panel in place, an impact driver is a big help.
  6. Look at the panel very carefully and mark any areas that need additional fitting work.  Rework these areas as necessary.
  7. Once you are satisfied with the fit, remove the panel and drill or air punch holes in the replacement panel every few inches on the weld flanges (the new areas that will be drilled will be similar to where the old panel’s spot welds were drilled).
  8. Re-clamp the panel in place.
  9. Next, begin to weld the panel in place.  Use the plug weld method, in which you weld through the hole of the new replacement panel, filling the hole which attaches it to the backing flange.
  10. After welding is complete, grind any excess weld buildup.  The welds should be flush with the new panel.  If you installed sheet metal screws to hold the panel in place, remove them now and then weld the holes shut.  Grind these welds flush also.
  11. Replacement is now complete and ready for any refinishing that you desire.

Copyright 2007:  FastbackStack, LLC

De-rust Your 1964 ½ -1973 Mustang Door

Original Mustang doors have rust. This is common knowledge that 40+ year old doors are going to suffer this fate. How do you handle this? What do you do when you discover rust on your classic Mustang door? We have an economic and environmentally friendly solution to this rusty problem.  This guide will give tips on how to de-rust the bottom section of your Mustang door, as this is the main area that problem rust occurs.

Rust on the inside bottom seam is not visible to the eye, but is generally present.  This rust causes the bottom edge of the door to swell if it’s not eliminated.  No amount of sandblasting will remove rust from this area.  Thus, utilizing this environmentally friendly chemical dip is imperative to remove this hidden rust before swelling occurs.

Materials Needed

  • 4 – 5 gallons Apple Cider or Distilled White Vinegar
  • 1 54″ long piece of PVC pipe (6″ or 8″ diameter)
  • 2 end caps
  • PVC pipe cement (glue)
  • Rust inhibitor paint (such as POR 15)

The Process

This process will walk you through creating a container made from PVC pipe that holds vinegar.  The bottom section of the door is then submerged in the vinegar.

  1. Prepare the door:  Complete any patchwork, sand off paint, remove excess rust scale, and clean the inside of the door with a vacuum or compressed air.
  2. Using PVC pipe cement, glue an end cap to each end of the PVC pipe.  Allow time for them to completely dry.
  3. Cut out a section of the PVC pipe large enough to fit the door in it.  Once cut, it will resemble a trough, and look like a canoe with two blunt end caps.  PLEASE NOTE:  You can use or devise a different non-metal container that suits your needs.  I have found that cutting PVC pipe in this manner works well.
  4. Fill the trough with 2-4″ of vinegar.  TIP:  large containers of vinegar are often sold at grocery outlet stores.
  5. Submerge the door in the trough and prop it up so that it won’t tip over.
  6. Leave the door submerged in the vinegar for 7 days.  Check progress after 7 days.
  7. If rust still appears, leave it submerged for another 7 days.
  8. Remove the door from the trough of vinegar and rinse the door with water.
  9. Place the door near a heat source where it can thoroughly dry on the inside and on the outside.
  10. Using compressed air, blow any remaining moisture and water from the groove located on the inside bottom section of the door.
  11. Apply rust inhibitor paint to the inside of the door, along the seam.
  12. Your door is now ready to have the body work completed.

Copyright 2007: FastbackStack, LLC

Sanding Body Filler on your Mustang

Freshly applied and cured body filler tends to clog sandpaper.  Here is a trick I have used to save a little time while also prolonging the life of my Long Board or Dual Action (DA) sand paper:

  1. Once the body filler has cured, take a piece of used coarse-grit sand paper and thoroughly scuff the body filler.
  2. Next, take a handful of fine, dry filler sanding dust and rub this dust into the freshly sanded filler.  If possible, wait a day or so to further dehydrate the filler.
  3. Then, place a new piece of sand paper on a sanding device of your choice.
  4. Now you are ready to begin sanding the body filler again.

Utilizing this tip helps to dehydrate the body filler, prevent paper clogging, and saves the amount of sand paper that you will go through.

Another Sanding Tip

  • When shaping body filler in a concave area (where the metal curves inward), wrap sandpaper around a rolled-up magazine.  This gives added flexibility, yet the length is stiff enough to be able to sand successfully.

Good luck with your body work and sanding projects on your Vintage Mustang!

Copyright 2007:  FastbackStack, LLC

Re-skin a 1967-1970 Mustang Fastback Trap Door

Often times Mustang Fastback trap doors (trunk access doors) have speaker holes cut in them.  Many people want to restore the trap door to it’s original condition, without speaker holes.  But how do you re-skin the trap door to properly repair this modification?  This guide is written to provide you with some tips for doing just this.  Please remember to indicate below if this guide is helpful to you!

Tools Needed

  • Spot Weld Driller
  • Drill
  • Hammer
  • Chisel
  • Pliers
  • Door Skinning Pliers
  • Felt Tip Marker
  • Metal Brake (optional)
  • Dolly

The Process

  1. Determine if the trap door frame has been cut.
    If the frame has been cut, we do not recommend you re-skin it.  Since the frame has been cut, the part is pretty much useless.  However, you could obtain a reproduction trap door and replace the reproduction skin with an original skin piece.  Why would you want to replace the reproduction skin?  Because the reproduction trap door skin texture does not come close to matching the original texture pattern, but the frame is okay to use.  If you are interested in doing this, proceed to Step 2.
    If the trap door frame has not been cut, you will be able to use your original trap door frame to apply an original skin piece.  Proceed to Step 2.
  2. Obtain an original skin piece.
    Where do you find an original skin piece?  Not all Mustang Fastbacks came with a trap door.  Some were equipped with an attached textured metal panel (skin piece) instead of the trap door.  You will want to find one of these textured metal skin pieces for use as your trap door skin.  Original metal skin pieces can ONLY come from a 1967 or 1968 Fastback that did not come equipped with a trap door.
  3. Compare the textured metal skin piece to the trap door skin.
    Lay both the trap door and the metal skin piece upside down to compare them.  They should be identical, with the exception of the skin piece not having the frame around it.
  4. Remove the damaged trap door skin.
    Using your spot weld driller, drill the few necessary spot welds that hold the skin to the frame (for more information, see our Drilling Spot Welds for a Unibody Panel Replacement guide).  Now, using your hammer, chisel and pliers, separate the metal skin piece from the frame by prying the edges of the skin that hold it to the frame.  This will remove the damaged metal skin piece from the trap door frame.
  5. Replace metal skin piece on frame.
    Carefully place the frame onto the backside of the replacement skin piece.  Center the frame evenly onto the skin piece.  Using a felt tip marker, mark the edges of the frame onto the skin piece.  You will now need to begin to bend the edges of the replacement skin piece around the edges of the frame, just like the original one used to be.  This can be expedited by pre-bending the edges of the replacement skin with a metal brake (a metal bending tool).  Pre-bend the edges to 90 degree angles.  Place the trap door frame into the prepared skin using your door skinning tool or pliers.  Completely pinch the trap door skin around the frame.  If additional tightening is necessary, use your hammer and dolly (a metal block that is used in conjunction with a hammer for straightening).
  6. Spot weld the skin to the frame.
    This step is optional, depending upon the results you want to achieve.  If you choose to spot weld the skin to the frame, spot weld the folded edges of the replacement skin to the frame as necessary.
    Your trap door is now ready to be stripped and refinished!  Trap doors are a nice option on a Classic Mustang Fastback or Shelby.  Utilizing these tips, you will be able to restore your trap door to an original condition while having a texture that matches the rest of the interior.

Copyright 2007:  FastbackStack, LLC

Quickly Clean your Mustang Nuts, Bolts and Brackets

I have discovered an amazingly easy way to way to clean a lot of small parts with very little effort.  If you own or have access to a cement mixer, this tip will be very useful to you.  The cement mixer, combined with sand-blasting sand, will automatically clean your parts for you!

Materials Needed

  • Cement Mixer
  • 1 bag (100 pounds) of sand-blasing sand
  • 2 five-gallon buckets (1 for parts, 1 for sand)
  • 1 section (1/4″ to 1/2″ mesh) chicken wire or comparable screening device

The Process

This process works well when cleaning heavy duty parts such as nuts, bolts, brackets, clips, rubber bumpers and bushings, spring plates, motor mounts and other comparable items.

  1. Start up the cement mixer.
  2. Pour in the parts to be cleaned.
  3. Pour in 1 bag (100 pounds) of sand-blasting sand.
  4. Lower the angle of the cement mixer down, keeping the angle of the mixer high enough so that the contents do not spill out, but low enough to thoroughly agitate the contents.
  5. Allow the cement mixer to run for approximately 4 hours.  Four hours should be adequate time for general cleaning.  Additional time may be required for cleaning excessively dirty parts.
  6. Place an empty five-gallon bucket under the mixer.  Using a strainer (chicken wire or screening device), slowly tip the cement mixer to allow the sand to fall through the strainer, leaving the parts on top of the strainer.

You have cleaned your parts without all the tedious work!  A “set-it and forget-it” process that yields great results.

PLEASE NOTE:  Do not attempt to clean delicate parts using this method.  Items such as horns, trim pieces, and brass parts will be ruined if you attempt to clean them this way.

Copyright 2007:  FastbackStack, LLC

Locating Spot Welds for a Unibody Panel Replacement

Drilling spot welds is an important step of the body panel replacement restoration process.  But, often times spot welds are difficult to locate.  Perhaps the vehicle is severely rusted or perhaps it has been painted several times.  Both rust and paint can cover up spot welds.  This guide will give some tips on how to locate seemingly invisible spot welds.

Tools Needed

Course Sand Paper:  40 grit or lower

  • Wire Brush
  • Flashlight
  • Chalk
  • Hammer
  • Flat Metal Chisel

Tips for locating spot welds

Spot welds can be covered with rust or paint.  Use these tips for finding them:

  • By hand, run course sandpaper over welded flange areas a few times.   This will remove rust and/or paint along the flanged areas but will leave traces of paint and/or rust within the low areas.  These low areas are the spot welds.
  • Run a wire brush over the welded area a few times.  This will yield similar results as using sandpaper.  The rust and/or paint along the flanged areas will remain and traces of rust and/or paint will remain within the low areas, or spot weld areas.
  • In a dim-lit setting, shine a flashlight at a very low angle along the welded flange.  Doing so will, in some cases, cast a shadow at each spot weld.  Then, mark this area with chalk.

Most spot welds are discovered by using the previously described methods.  In case there are additional welds that are undetected, try this tip:

  • Using your hammer and chisel, begin to remove the panel by laying the flat edge of the chisel between the panels and gently hammering until the chisel comes to a stop.  Often times, it is hitting the spot weld.

Now that you have located all of the spot welds, you are ready to drill the spot welds.  Please see our guides on Drilling Spot Welds for a Unibody Panel Replacement and Unibody Panel Replacement for more helpful tips.

Copyright 2007:  FastbackStack, LLC

Drilling Spot Welds for a Unibody Panel Replacement

Drilling spot welds to remove unibody panels such as your cowl, rear quarter panel, floor pans and wheel wells can be tedious, but it is a fairly straightforward process.  This guide will help you tackle spot weld drilling like a pro.  Please remember to indicate below if this guide is helpful to you!

Tools Needed

  • Sand Paper and/or Wire Brush
  • Drill
  • Pilot Drill Bit: 1/8″ diameter
  • Spot Weld Cutter: 3/8″ diameter
  • Heavy Oil
  • Hammer
  • Flat Metal Chisel

Spot Weld Drilling Process

  1. Locate the spot welds needing removal
    This is done by looking for small, round depressions located every few inches where the body panel is attached to the vehicle.  If your vehicle is severely rusted or has been painted several times, these welds can be difficult to locate.  You would then need to clean the spot weld areas with sand paper or a wire brush to locate the welds.  Please see our  Locating Spot Welds for a Unibody Panel Replacement guide for more information.
    The drill bit is pointing at the small depression/spot weld.

    The drill bit is pointing at the small depression/spot weld.

  2. Using your 1/8″ drill bit, drill a pilot hole through the center of each weld
    A pilot hole is a centering hole for the spot weld cutter.  Helpful tip:  Dip the tip of your drill bit in heavy oil prior to drilling each spot weld.  This will prolong the life of your drill bit.
    This picture shows the pilot hole being drilled.

    This picture shows the pilot hole being drilled.

  3. Once all pilot holes are drilled, use your spot weld cutter to drill a hole through each spot weld.
    Using a specialized weld cutter minimizes the damage to the panel underneath the panel being removed.  When drilling with the weld cutter, only drill deep enough to remove the desired panel.  When I drill a weld, I watch the drilling area change from clean metal to light surface rust.  This would indicate that I have just reached an area between the sheet metal panels.  At this time, there is usually a little “poof” of rust dust.  I stop at this point, since I know I have just drilled through the first panel without over-cutting the second panel.
    Here is one style of weld cutter.  This is a sheet metal bit, 3/8" size.

    Here is one style of weld cutter.  This is a sheet metal bit, 3/8″ size.

    Here is the weld cutter at work, drilling the top layer of the spot weld.

    Here is the weld cutter at work, drilling the top layer of the spot weld.

    The weld is drilled!

    The weld is drilled!

  4. After all welds have been drilled, carefully use your hammer and flat chisel to separate the panels.
    This is done by laying the flat edge of the chisel between the panels and gently hammering to loosen any bits of weld that were not cut by the drill.
  5. Now that your panel is removed, you are ready for the next process.  Please see our Patch Panel Installation – Unibody Panel Replacement Guide for further information.

You are on your way to spot weld drilling!  I have drilled over 5,000 spot welds throughout the last 15 years and I will probably drill 5,000 more in this year alone!

Copyright 2007:  FastbackStack, LLC

1965-1973 Ford Mustang Headliner Installation

Installing a new headliner into your Mustang is probably your first step when restoring your vehicle.  Use this “how-to” guide to help during this installation process.  I have installed many headliners and used to install headliners using clamps until I came across a new trick of using cut up pieces of windlace instead of clamps.  I’ve found that this way is much easier and tends to yield better results.  Installing a headliner should not be intimidating.  You can save a few hundred dollars by doing the installation yourself, while at the same time fostering the pride of completing this task all on your own.


  • Headliner
  • Sharp Scissors
  • Razor Blade or Sharp Knife
  • 3M Spray Adhesive
  • 32 Pieces of Cut Up OLD Windlace (cut into 2″ pieces)
  • New Windlace Strips


  • Bow– the metal rods that hold the headliner against the roof of the car.  Mustang Coupes generally have four bows, while Mustang Fastbacks generally have three bows.
  • Windlace – the long plastic trim cap that runs alongside the door glass seal on the body.
  • Moonskin – the texture of the headliner material.
  • Roof Rail – the part of the roof frame where the headliner bows insert into.

Installation steps:

For best results, remove the windshield, rear window and weather stripping channel in the door openings.  It is VERY difficult to tuck and secure a headliner without removing the glass (besides, it will look horrible and have wrinkles if this is attempted).

  1. Before starting, lay your new headliner flat to remove any folds or wrinkles.  It may help to lay it in the sunshine to make it more pliable.
  2. Completely remove the old headliner, while taking note of exactly where the headliner bows are placed (this information will help you when installing the new headliner).  SPECIAL NOTE – it is important to know that each bow may vary a little in length and curve.  It may help to number the bows as you remove them and assign a numerical number from front-to-rear, while laying the bows in the order that you will insert them again into your new headliner.
  3. If the old insulation pad is still intact and in good condition, you may reuse it (depending upon your degree of restoration, you may choose to reuse the pad or purchase a new one).  If the pad falls apart, find a new insulation pad and securely glue it in place by spraying both the pad and the roof with 3M Spray Adhesive.
  4. While using your metal headliner bows that you have numbered from front-to-rear, begin with the forward-most bow piece and slide the metal headliner bows into the forward most sleeve of the new headliner.  Repeat the same steps with the other numbered bows, continuing to work from front-to-rear.
  5. After all bows have been inserted and CENTERED into the headliner sleeves, trim the excess sleeve material back, exposing about two inches of both ends of all the bows.  When trimming, just trim the excess SLEEVE material…DO NOT TRIM THE MOONSKIN YET!
  6. DSC01020 DSC01022

  7. Next, begin to insert the headliner into the vehicle, starting with the rear bow.  Insert the rear bow into the holes of the roof rail.  Then insert the other bows into their corresponding holes of the roof rail.  Your headliner will be “baggy” and hanging at this point.  The bows are hanging downward.
  8. Beginning with the front bow, rotate the bow so that it is snug against the ceiling of the vehicle.  Repeat this step, working from front-to-rear, until all bows are snug against the ceiling of the vehicle and are no longer “baggy”.  The bows are now upright and in the correct position.
  9. Working with the rear bow, hook the center of the bow with the two springs that connect to the rear window opening (you probably noticed these two springs when you removed your old headliner).  SPECIAL NOTE – If the two springs are in poor condition, find a suitable replacement (I have actually used spring steel wire and cut and bent it to fit as a replacement).DSC01028
  10. Now it is time to begin to stretch your headliner.  This is where the old cut up pieces of windlace comes in handy!  Starting in the center of the front windshield opening, pull the headliner material gently through the windshield opening, holding it on the roof, and secure it with a few pieces of windlace.  This is done by pushing a piece of windlace (using the channeled groove) onto the sheet metal edge of the window opening.  This will hold the headliner securely to the sheet metal.  Repeat this step at the rear window opening, again using windlace to secure the headliner to the sheet metal.  Best results are achieved when using approximately eight pieces of evenly spaced windlace at both the front and rear windshield areas.

  11. Next, continue to stretch and secure your headliner to both door window openings.  Again, use approximately eight windlace pieces per side.  Thus, you have now used 32 pieces of windlace.  SPECIAL NOTE – for a Mustang Coupe, the rear pillar has a metal tack strip that holds the headliner in place.  You’ll achieve better results if you keep stretching and re-securing the rear pillar portion of the headliner.  This needs to be done carefully, as the headliner may begin to tear.  I have found it helpful to cut a piece of window screen, spray it with adhesive and stick it to the back of the headliner where the tack strip will puncture the window screen.  This aids in preventing any serious rips in the headliner.
  12. Do a visual check of your headliner to locate loose or wrinkled areas.  If these areas are present, continue to work your way around the vehicle, removing windlace pieces and gently pulling the headliner and re-securing the windlace pieces.  The headliner should be wrinkle-free, but not too tight.
  13. The headliner is now ready for adhesive.  Remove 3 or 4 pieces of windlace from one area (I usually begin with the windshield area opening).  Spray adhesive on the headliner backing and on the metal window opening edge.  DO NOT ATTACH THESE TOGETHER YET!  Allow a few minutes for the adhesive to dry before re-securing the headliner to the metal window opening edge.  This is the recommended method of the spray adhesive (see the adhesive can for further instructions).  Once the adhesive is ready, re-secure the headliner to the metal window opening edge.  Repeat this step until all edges are glued.
  14. Now the headliner is ready to trim.  DO NOT REMOVE THE WINDLACE PIECES YET.  Using a sharp razor blade, carefully cut the excess headliner from the front and rear window openings.  Leave about 3/4″ of headliner material so the rubber window seals will cover them when later installed (REMEMBER, DO NOT REMOVE THE CUT WINDLACE PIECES FROM THE FRONT AND REAR WINDOW OPENINGS UNTIL THE GLASS IS TO BE INSTALLED).
  15. For the side window openings, have your brand new windlace strips ready.  Remove one windlace piece at a time, while pressing your NEW windlace strip in place.  Doing it this way will prevent any headliner movement.  Do this to both window openings, installing both NEW strips of windlace.
  16. Now the sides of the headliner are ready to be trimmed.  Simply run a razor blade along the outside edge of the new windlace strip.  Do not leave any extra headliner material hanging on the outside edge of the windlace strip (installing the weatherstrip channel will hide the outside edge of the windlace).
  17. The headliner is almost complete.  Now, you’ll need to finish the inside windshield pillars.  Locate the screw hole for the trim piece that covers the seam and cut the headliner so that the trim piece will hide the edge of the headliner material.  This may require some adhesive.  Repeat this step with the rear window opening (that is, if are installing a Fastback Headliner).  SPECIAL NOTE – For a Mustang Coupe (referring back to STEP #10), re-stretch the area if necessary.  The rear pillar of a Coupe is the most challenging area to achieve wrinkle-free results. 

Congratulations! Your headliner installation is complete.

We hope these steps have been helpful, especially using the tricks with the cut up pieces of windlace.  If you are an experienced headliner installer, perhaps this guide offered you some new tricks to try during your next headliner installation.

Copyright 2007:  FastbackStack, LLC