Ok, Got the 70-72 full quarter to fit right, now how do I weld it to the body. I seem to recall someone on this site saying to drill holes where the original factory spot welds were and plug weld the quarter on.

Is this how most of you did it or did you use some other method?

When using a MIG welder, plug welds will get you the best penatration and strength. You should, however, place more plug welds than there where factory spot welds. I usually do about twice as many.

Trooper

If you plug weld it, it should contain the same number and in the same spot as the OEM locations.

Try doing a search for quarter replacement.

I'm starting this project as well and would like to know which way it is... same number or twice as many? And why? :\

The same number!!!

EVERY repair manual will back that statement.

Not so much with full frame cars but with todays unibody cars you weld a quarter on with twice as many spot welds you CHANGE the strutucal intergity of the car and how it can react in a future collision

Something from a Ford Explorer repair manual about welding:

SECTION 501-25: Body Repairs — General Information 2002 Explorer/Mountaineer Body Collision Repair Manual
DESCRIPTION AND OPERATION Procedure revision date: 06/19/2002

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General Information —Welding Techniques

Preliminary

When welding is performed anywhere on the vehicle, safety precautions must be taken to prevent damage to electrical system wiring or components. Any parts which could be damaged by excessive temperatures or electronic surge should be removed or correctly shielded.

Begin by disconnecting and covering the battery negative cable. Disconnect the vehicle control modules such as the ABS control module, the restraints control module (RCM) and the powertrain control module (PCM). Additionally, computer processors should be completely removed if welding is to be done within their proximity.

Safety precautions to observe during welding include the following:

Do not allow electronic units or lines to come into contact with the ground connection or the welding electrode.
Completely remove the battery if carrying out welding work in its vicinity.
Utmost care must be taken when welding near the fuel tank or other components that contain fuel. Remove them if there is any doubt.
Connect the ground connection of the electrical welder directly to the part that is to be welded. Make sure that there are no electrically insulating parts between the ground connection and the welding point.
Adjacent vehicle parts and adjacent vehicles must be protected from flying sparks and heat.
Most welding in production is accomplished by resistance spot welding. When making repairs, the joining technique to be used in collision repair should be MIG plug welding. The number, location and diameter of repair plug welds must be the same as in production. Alternative joining techniques must only be used in exceptional cases.


Equipment Set-up

Welding repairs can only be carried out correctly if the equipment is set up correctly and all the welding parameters are coordinated as listed below:

Always read and follow the equipment manufacturer's instructions for the equipment settings.
Hoses must be untwisted.
Cores must be free of abraded rod particles.
Gas and current nozzles must be free of slag and scale residue.
Pay attention to the quality of the welding wire and the throughput of gas.
Make sure that joint surfaces are perfect.
Make sure that flanges to be joined lie perfectly flat to one another.
Prepare a bare metal joint surface (inside and outside).

Setting Up the Flow Meter (or Pressure Gauge)

Set up the flow meter as follows:

Inspect the flowmeter for oil, grease, or damaged parts. Do not use if any is found.
Flow meters are calibrated for a specific gas. Verify that the pressure source gas is the same as marked on the flow meter.
Attach the flow meter to the pressure source. The flow meter must be in the vertical position to read accurately.
Make sure source gas is fully open.
Check the joints between MIG welder and meter for leakage and make sure they are tight.
Before turning on the pressure to the flow meter, make sure the flow control valve is in the closed position by turning the knob counterclockwise until it stops. Tighten finger-tight; do not force.
Open the flow adjusting valve to attain the desired flow rate. Engage the trigger and verify the flow rate.

MIG Wire

Wire electrodes for MIG welding should conform to the American Welding Society (AWS) standards. Each wire type has its own AWS standard. Each AWS standard has its own number. The wire number lists the wire: type (rod or electrode or both), minimum tensile strength (70 = above 70,000 psi), coatings (S = bare wire), and chemical composition. The chemical elements are carbon (C), manganese (Mn), Silicon (Si), phosphorous (P), sulphur (S), nickel (Ni), chromium (Cr), molybdenum (Mo), vanadium (V), copper (Cu), titanium (Ti), zirconium (Zr), and aluminum (Ai).

The AWS standard will be found on the wire spool. Example: ER70S.


Equipment Care

Follow these general recommendations to make sure the welding equipment is maintained in good condition:

Do not lubricate welding equipment, especially the threads on the nuts that attach hoses. If oxygen strikes oil or grease it can burst violently into flame.
MIG welding equipment is electrical and the general care of any electrical tool applies to this equipment. Because arc welders use a low voltage with high amperage, the chance of a severe shock is minimal.
Take care of welding cables and make sure that they are not stepped on or driven over. Install a new component that has damaged insulation or other problems.
Take care when storing gas welding equipment. The welding gases must be kept away from excessive heat, flames and general traffic. A separate room for storage is preferable and cylinders should be retained so they cannot fall.

Anti-Corrosion Materials

Anti-corrosion materials must be used to restore the corrosion protection after a repair because heat from welding will destroy the factory protection in three areas of the weld. The three areas are:

The surface or actual weld area
The area between the two metals that are welded
The surface behind the weld area
An example of anti-corrosion materials is: Super Seal Anti-Corrosion Compound (Motorcraft TA-8).


Surface Area

The surface area must be prepared properly before applying paint. Without the proper area preparation, the rest of the repair procedures and corrosion protective efforts will be wasted. There are four steps in preparing the area:

Use a wax and grease remover and a clean cloth to clean and remove all contaminates.
If required by the paint system manufacturer, deep clean the metal by using a metal conditioner. Follow the paint system manufacturer's application recommendation.
If required by the paint system manufacturer, apply a conversion coating to the surface area. Be sure to use the correct product for each type of surface and follow the manufactures recommendations for application.
The mating surfaces of panels to be joined by welding must be prepared prior to the welding process. Dirt, grease, oil, paint, and E-COAT must be removed. Galvanized coating to be removed through the use of a disc grinder. Corrosion protection will need to be restored before welding due to the grinding of these panel surfaces.

Primers rich in zinc content which will offer corrosion protection during and after welding.

Once the panels have been prepared (Galvanizing, Paint, etc. have been removed), position and clamp the panels in place. Welding procedures may now be carried out.


Behind Metal

NOTE: Do not drill access holes. Use existing holes in the body panels to apply anti-corrosion materials.

Anti-corrosion compounds are used where it is difficult to get primer coverage. This includes such areas as the back side of welded parts with boxed cross-sectional structures, such as side members and body pillars that cannot be painted.

Anti-corrosion compounds are either wax-based, light-bodied materials or asphalt-based materials. These materials are designed to coat and protect exposed and unexposed areas such as the exterior body panels, inner surfaces, unibody structural boxed sections and to penetrate between metal-to-metal surfaces such as pinch-weld joints and hem flanges.

When body repair work is done, corrosion protection must be restored to all repaired areas.

Insert a flexible wand through existing holes in structural rail boxed sections to apply anti-corrosion materials.


Sealers

In addition to repairing the weld area, proper sealing of the joints is essential to a quality repair. Sealers are intended to prevent wind noise, water, dust and exhaust fumes from entering the vehicle and also perform as anti-corrosion barriers. Sealers need to be applied to such areas as door and rear compartment lid hem flanges, wheelhouse, quarter outer, floor, cowl, roof and various other panel-to-panel attaching points. The following joint sealers are recommended for use depending upon the application:

Brushable Seam Sealer — A sealer intended to restore the original brushed seam look. It is used to seal lap joints in sheet metal that are spot welded, such as on floorpans, cowls, trunk seams, etc.
Joint and Seam Sealer — A firm setting but flexible sealer for interior and exterior joints and seams.
Drip-Check Sealer — A heavy bodied sealer designed for use on exposed seams.
Sealers should remain flexible after curing and must be paintable. Follow the manufacturer's directions for use of materials selected.

Any damage to originally sealed joints should be corrected by resealing. Along with attaching points of new panels, open joints which require bridging of sealer to close a gap should be sealed using a heavy-bodied sealer.


Removing Welds

The most common method of removing spot welds on sheet metal panels is through the use of either a 7.75 mm (0.312 in) spot weld cutter or a combination of 3 mm (0.125 in) and 7.75 mm (0.312 in) drill bits. On heavier gauge materials such as frames, the 3 mm (0.125 in) and 7.75 mm (0.312 in) drills will also be used. However, the spot welds on these mating surfaces will require a complete drill through.

Spot Weld Cutter
Spot weld cutters are similar to a hole saw in a much smaller size. Spot weld cutters remove the metal around the spot weld. This type of tool requires the use of a drill (air or electric). Position the spot weld cutter pilot tip in the center of the spot weld and drill around the weld until the outer panel has been drilled through. Pay particular attention to the spot weld cutter manufacturer recommendations for maximum revolutions per minute (RPM) rating. An air chisel and bit may be required to separate the panels in areas where the entire weld has not been cut away. This method will require grinding away the spot weld nugget from the inner panel when finished. Should the spot weld cutter drill through both the inner and outer panels, the inner panel hole should be welded closed using a MIG welder, and then grind smooth.

3 mm (0.125 in) and 7.75 mm (0.312 in) Drill Bits
Begin by using the 3 mm (0.125 in) drill bit and drill a pilot hole all the way through the center of the spot weld. Using the 7.75 mm (0.312 in) drill bit, drill through the spot weld until removed. With care and practice, the spot weld may be removed without drilling through both panels. An air chisel and bit may be required to separate the panels in areas where the entire weld has not been cut away. When the inner and outer panels have been separated, the inner panel hole should be welded closed using a MIG welder, and then grind smooth.

Plasma Cutter
Another option for weld removal is through the use of a plasma arc cutter. This technique requires the weld area be cut around as with the spot weld cutter. However, while use of the plasma arc cutter may be faster, it will remove the material around the weld on both the outer and inner panel. Close all inner panel holes using a MIG welder and then grind smooth.


Weld Defects

The following list identifies possible defects that may occur, and how to prevent them:

Arc Hard to Start — This condition may arise because of incorrect settings, dirty work surfaces, or improper grounds. In addition to using the correct settings, you should make sure the work piece and the welding equipment are clean and that a good, solid ground is established.
Cracked Welds — Cracked welds usually occur because the incorrect wire type was used, the weld cooled too quickly, the base metal is high-carbon steel, or the work piece was unbalanced in gage size or material. Make sure the wire is the correct type. Allow the weld to cool naturally and make sure the work is secured correctly.
Distortion — Distortion can happen as a result of uneven heating or if the heating is too high. Work pieces that are incorrectly placed can also cause distortion. The pieces being worked on should be clamped correctly. Always allow enough time to cool in between welds and use short beads. Keep weld deposits to a minimum.
Excessive Spatter — Using current settings that are too high, wrong polarity or wire type, or arc lengths that are too long can result in excessive spatter. Use the correct settings and wire types.
Incorrect or Shallow Penetration — Incomplete weld penetrations are the result of utilizing weld speeds that are too fast, wire size that is too small, current settings that are too low, weld grooves that are too small, or impurities in the base metal. Use the correct speed, settings, and wire size. Clean the work piece. Make sure that the bottom of the joint has enough room for the weld.
Poor Fusion — Poor fusion of the work piece can be caused by current settings that are too low, incorrect welding speed, wrong wire type, arcs that are too long, incorrect welding angle, or improper preparation of the work area. Use the correct settings and speed. Make sure that the work is properly prepared.
Poor Appearance — Incorrect settings, poor operator technique, or incorrect wire types are the main causes of welds that have a poor appearance. Use the correct settings and equipment and use proper welding techniques.
Porous Welds — Porosity is caused by short arcs, incorrect speeds, impurities in the base metal, insufficient puddling time, or gas flow. To avoid porosity, always allow a puddling time sufficient enough to allow gasses to escape by thoroughly cleaning the base metal, and using correct gas flow.
Undercutting — Undercutting is caused by settings that are too high or speeds that are too fast. Undercutting can also be caused by incorrect arc length. Use the correct settings and speed. Hold the arc at the correct length.

Plug Welding

Follow these general recommendations while plug welding.

Carry out a test weld on a sample piece of the material.
The power needs to be adjusted for high-strength, low-alloy steel.

MIG Welding

MIG welding is the preferred method of welding for auto body repairs, primarily due to reduced heat effect zone. The heat effect zone is the area around the welding zone that is affected by heat generated during the welding process. This is important because the heat can weaken the area directly around the weld.

Aluminum, magnesium, stainless steel, carbon steel, alloy steels, and other widely used metals can be welded using the MIG process. Welding currents of 80-100 amperes are commonly used at welding voltages of 15 to 32 volts.

The short arc welding method is the preferred method for automotive body work. In short arc welding, metal is deposited each time an electrical short circuit is established.

Any joints that are MIG welded in production must also be MIG welded during repairs. During repairs, some resistance spot welds need to be replaced by plug welds.

A test weld should always be carried out to make sure that the welded joint is not just a surface connection.
Attach the ground cable right next to the welding point (make sure that good contact is made).
During plug welding, start welding on the lower panel to insure adequate penetration.

MIG Welding Procedures for Aluminum

Cleaning
Proper cleaning precautions must be taken to assure a quality aluminum weld procedure. The following recommended steps should be adhered to before performing any aluminum welding procedure.

NOTE: The use of an oil/wax/grease remover that evaporates completely and leaves no film or residue is essential to assure a repair free of contaminates.

Use a clean cloth to apply an oil/wax/grease remover to the repair area.
Use a stainless steel wire brush to scrub the area clean.
Reapply the oil/wax grease remover.
Welder Set Up
The MIG welder should be operating in a DC reverse polarity operating mode. This is the standard polarity used for MIG welding steel and therefore requires no polarity adjustments. The reverse polarity action helps clean the metal surface of any remaining aluminum oxide while welding is taking place.

100% argon shielding gas is used for aluminum welding. The shielding gas flow should be set to a 14-24 liters/hour (30-50 cubic feet/hour) flow rate. This is about 50% higher than required for steel welding.

The welding wire diameter should be 0.8-0.9 mm (0.030-0.035 inch). A 4043 alloy wire should be used for all alloys except the 5000 and 6000 series, where a 5356 alloy wire should be used. A TeflonŽ liner is used in the MIG welding hose to minimize any restriction to wire flow and to prevent any contamination of the wire from the steel liner. Care must be taken not to scratch the liner with the wire. The end of the wire should be de-burred before it is inserted into the liner.

Most liners can be changed by following these steps:

Remove the gun and hose assembly from the welder.
Remove the nozzle, contact tip, and gas diffuser from the end of the gun.
Loosen the set screw holding the end of the liner in place at the machine end of the hose. Some guns have a second screw on the gun which must also be loosened.
Pull the steel liner out of the hose assembly. Insert the TeflonŽ liner while keeping the entire length of the hose straight. Snug the set screw at the inner end of the hose and follow the manufacturer's recommendations for trimming the TeflonŽ liner to length.
Lightly snug the outer set screw, if equipped.
Replace the gas diffuser, contact tip (checking for correct size), and nozzle.
The tension setting on the drive rollers is crucial to proper performance of the MIG when welding aluminum. Too much tension will distort the soft aluminum wire and could cause a bird nest problem should wire movement be obstructed at the gun. Trim any excess wire with wire cutters while the MIG gun is pointing away from the operator.

Spattering from aluminum welding tends to adhere more readily to the contact tip than welding steel. An anti-spatter spray should be applied to the inside of the nozzle to minimize spatter buildup.

For most welding applications, the distance between the contact tip and the base metal should be 8 mm (0.32 in) to 15 mm (0.6 in), depending on the heat (voltage) setting of the welder. This is similar to steel welding.

When the welder is properly set, the wire speed will be higher than the speed used for welding steel. The wire speed is set in a similar fashion to welding steel. A continuous "sizzling bacon" sound indicates proper wire speed.

The gun travel speed is higher than for welding steel. The gun speed also increases as the welding progresses due to the higher thermal conductivity of aluminum.

It is important to use the push method while welding.

A small amount of soot may form along the weld bead and is caused by a small amount of magnesium in the aluminum alloy.


Butt and Lap Welding (Steel and Aluminum)

The same cleaning steps apply as in plug welding. For butt welding, sand a width of approximately 20 mm (0.8 in) total on the top side and 10 mm (0.4 in) on the bottom side. For lap welding, the oxide layer must be cleaned from the top and bottom surfaces of the top piece and from the top surface of the lower piece.

When butt welding material less than 3 mm (0.12 in) thick, a square edge is required. For material over 3 mm (0.12 in) thick, prepare a 60° V-shaped joint. Clean the width of the V on the top edge three times. When doing multi-pass welding on thick material, clean the bead with a stainless steel wire brush in between passes.

The panels should be tack welded to prevent strain and maintain edge alignment. Use short tack welds on thin plate and avoid tack welding the ends or corners of the base metal.

When lap welding, the panels must fuse together firmly to avoid plate separation. Penetration will occur easily on the top layer of metal. Care must be taken to assure adequate penetration of the lower piece of aluminum or steel. A gun angle of 10 degrees to the base plate and a 5-15 degrees forehand motion should be used.

The ideal size of the bead in a cross-sectional view is the same size or slightly larger than the plate thickness.

If a crater forms at the end of a bead, it must be filled for adequate strength. The crater can either be filled by stopping the gun motion temporarily prior to switching off the power or by switching off the power and then turning it back on again to fill the crater.

When grinding welds, use a 36-grit disc to remove the roughing area leaving some material for a finishing allowance. Use a 80-grit sander for sanding the finishing allowance. Use light pressure when grinding or sanding to keep heat buildup to a minimum.


Seam (Stitch) Welding

To reduce the distortion of the metal when seam welding, stitch weld in increments of 19 mm (0.76 in).

The wire must be extended so that the nozzle is 6.35 mm (0.25 in) from the work.
The tip of the welder must be held at a 30° to 45° angle.
To prevent distortion, do not weld more than 19 mm (0.76 in) at a time.
Allow time for the weld area to cool naturally.
Rotate welds until a full weld is formed.

Arc Welding

Arc welding is an acceptable method for welding heavier metal components, such as frame parts. In most cases, DC welding is the preferred choice for arc welding. AC arc welding is a preferred method when "arc blow" is a consideration. Arc blow is the tendency for the arc to bounce back, such as when trying to weld in a corner or other tight spot. AC arc welding tends to reduce arc blow.

There are two types of DC arc welding; DC- and DC+. DC- arc welding is when the arc flows from the electrode to the metal work surface. DC+ arc welding is when the arc flows from the metal work surface to the electrode.

When using an arc welder, keep in mind the following points:

Attach the ground clamp as close as possible to the work area.
Choose welding electrodes according to the type of steel, thickness and the polarity of the arc welder (AC or DC).


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Dang nice article Sevt.
I am so glad you are out here, with you were in Texas. Thanks again!

WOW. That was quite and article with a wealth of information. Thank you very much. Kind of "Nuked" it out for me, but basically where I was going with it.

Thanks again

Very good stuff Eric. I think what it comes down to is if you are replacing a weld with a "smaller" weld, you have to increase the amount of welds. For instance, my STRSW at work is set up to weld 6mm welds. Well, most all cars these days have 8mm spot welds. So, when replacing a panel on one of these cars I increase the welds by approx 25%. In the ICAR manual it reads;
"Vehicle makers generally recommend more collision repair spot welds than original welds"
The weld "AREA" is what you need to be concerned with on a unibody. There are all kinds of recommendations by manufactures such as Mazda, and others who want you to have a diameter weld that is two times the thickness of the metal being welded PLUS 3mm.

On a sixties full frame car, this is pretty much a moot point. Honestly, they are SO strong, the car is dangerous under most light to medium hits. There is basically no crumple zone or anything of the sort designed into these cars. They believed the stronger the better, which is simply not true.

By the way Eric, I have to thank you again (and I will continue to do this from time to time, sorry). I was welding in the trunk of my sister-in-laws 65 Mustang Fastback a few days ago. I had forgotten my welding respirator at work and put a nice fan under the car so blow the fumes away. If you had not brought the dangers to my attention I, first wouldn't even be wearing a respirator. Second, even though I do us one I would have welded this "little" project without it and thought "it is only a few welds" (about thirty). Stuck inside of that trunk full of zinc fumes would likely have caused some serious damage to this old boy. I am very greatful to your persistance in this matter of welding safety.

Thanks again. smile.gif

Originally posted by Monalizaf:
Ok, Got the 70-72 full quarter to fit right, now how do I weld it to the body. I seem to recall someone on this site saying to drill holes where the original factory spot welds were and plug weld the quarter on.

Is this how most of you did it or did you use some other method? I drilled holes on my new quarters or on the car side lips depending on how I could get in there with the welder (this was noted and done when fitting the new quarters originally while doing a dry run on them to see what needed to be done so I wasn't painting myself into a corner).
I used 3/8" holes and prepped the lip without the hole on it to remove and rust or paint on it so I got a good weld.
I also used clamps next to the hole I was going to plug weld to pull both pieces tightly together.
I put as many or more plug welds than what was there originally and spent the time with a hammer and dolly or pliers to get the lips on each piece flat to each other as I noticed originally that the factory spot weld tongs really pulled on some lips to stretch them closed and left gaps between the lips.
I used a lot of clamps or self tapping screws to first position the quarter panel to make sure everything lined up and then did some plug welding in one area and then jumped to another area and all over while constantly checking the alignment and eventually got it all done.
With spending the time on prep work and not being in a rush they came out better than how the factory ones were installed.
Jim

Originally posted by MARTINSR:
I am very greatful to your persistance in this matter of welding safety.

Thanks again. smile.gif Brian, thanks for the kind words. Just glad someone was listening.
You know if it wasnt for you I would have never bought that spot weld drill or those snap on panel poppers graemlins/thumbsup.gif

You ever make your mind up about stepping up the ladder? ;)