Acura NSX 1995 User Manual

1995 Model Series NSX/NSX-T Body Repair Manual

INTRODUCTION

How to Use This Manual

Body Repair

Preparation of Work

This manual covers the repairs of 1995 model series NSX/NSX-T* automobiles that have been involved in accidents, and it describes the work related to the replacement of damaged body parts.

Please read through these instructions and familiarize yourself with them before actually using this manual. NOTE: Refer to the applicable NSX/NSX-T Service Manual and Supplements for specifications, wire harness locations, safety stand support points, etc. *: In this manual text body type is mentioned. So they are NSX: Coupe, NXS-T: NSX-T (open top).

Special Information

WARNING

Indicates a strong possibility of severe personal injury or death if instructions are not followed.

CAUTION

Indicates a possibility of personal injury or equipment damage if instructions are not followed.

NOTE: Gives helpful information.

CAUTION

Detailed descriptions of standard workshop procedures, safety principles and service operations are not included. Please note that this manual does contain warnings and cautions against some specific service methods which could cause PERSONAL INJURY, damage a vehicle, or make it unsafe. Please understand that these warnings cannot cover all conceivable ways in which service, whether or not recommended by Honda, might be done or of the possible hazardous consequences of each conceivable way, nor could Honda investigate all such ways. Anyone using service procedures or tools, whether or not recommended by Honda, must satisfy himself thoroughly that neither personal safety or vehicle safety will be jeopardized.

Aluminum Alloy Repair

General Information

Replacement

Cross Section of Body and

Sealants

Body Dimensional

Drawings

Rust-preventive Treatments

All information contained in this manual is based on the latest product information available at the time of printing. We reserve the right to make changes at any time without notice. No part of this publication may be reproduced, stored in retrieval system, or transmitted, in any form by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. This includes text, figures and tables.

HONDA MOTOR CO., LTD.

Service Publication Office

Paint Repair

Body Paint Repair

Resin Parts Paint Repair

(Exterior)

Service Precautions

General Safety Precautions

Preparation of Work

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Description

• Most monocoque bodies are composed as a single unit by welding together pressed parts made of steel plates which come in a variety of different shapes and sizes. Each part is responsible for displaying a certain strength and durability in order that it may play its role in meeting the functions of the body as a whole.

• The NSX/NSX-T has an all aluminum monocoque body made of the aluminum alloy. Generally speaking, the collision damage of

the aluminum alloy body is not very different form that of the steel plate body.

Damage to the exterior of the body can be inspected visually, but where there has been an external impact, it is necessary to inspect the extent of the damage. In some cases, the deformation has spread beyond the actual areas which were in the collision and so this has to be inspected closely.

Checkpoints

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• Accurate Inspection of Damaged Parts (Visual)

Seat Belts

Always replace the seat belt if:

1. The belt material is cut, punctured, burned or in any way damaged.

2. The buckle or retractor does not work properly.

3. They were being worn at the time of a collision (check for damage at the seat belt anchor points).

4. Their condition is questionable.

Front Section:

1. Is there any bending, splitting, denting or other damage to the suspension and its related parts?

2. Is there any deformation of the front bulkhead or radiator core? Have any of the connected sections come apart?

3. Are there any creases or distortion in the front wheelhouse or side frame? Have any of the connected sections come apart?

4. Is there any bending or twisting of the whole front area?

5. Is there any deformation like creases, bulges, or dents in the front pillar, dashboard, floor, etc.?

6. Is there any vertical twisting or misaligned clearance in the door?

7. Is the windshield seal broken?

8. Is there any deformation in the vicinity of the top part of the roof panel's center pillar?

9. Is there any damage inside the automobile (is there any twisting of the dashboard, or anything irregular with the clearances or sheet-mounting parts)?

10. Is there any damage to the steering wheel? Is there any deformation in the column and the column-mounted parts?

Rear Section:

1. Is there any twisting, bulging or denting of the rear floor and rear bolsters? Have any of the connected sections come apart?

2. Is there any irregular bulging or denting in the rear fender?

3. Is there any distortion in the rear inner panel? Is there any bending and denting in the vicinity of the rear pillar?

4. Is there any distortion or creasing in the rear wheelhouse and arch sections? Have any of the connected sections come apart?

5. Is there anything irregular in the rear glass seal clearance?

6. Is there any twisting or misalignment of the clearance of the trunk lid opening section?

7. Is there any bending, splitting, denting or other damage to the suspension and its related parts?

8. Is there any deformation oh the rear floor cross member, trunk front panel and damper base? Have any of the connected sections come apart?

9. Is there any oil or water leakage and damage to the engine, transmission or brakes?

10. Is there any irregular noise in the gear changing operation, engine and transmission rotation?

11. Are there any traces of contact between the engine block and the center cross member?

12. Is there any damage to brake or fuel lines, or wire harnesses?

Preparation of Work

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Correction of the Damaged Area

Set the frame corrector on the car body.

The side sill is flangeless to allow reshaping by pulling it out.

Use the horizontal pinch welds for anchoring the car.

1. Apply load to the damaged section and pull it out until the

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section is almost restored to the original shape.

5. Decide whether to cut the weld joint parts and replace partially, or whether to replace all the parts.

2. Check that the parts of the body they cover have been more or less restored to their original shapes.

NOTE: As work-hardening occurs to the buckled section of the aluminum alloy, it can crack easily. Heat up the damaged section with an acetylene welder and pull it out to reshape it 1184°F (640°C) is the melting point of the

aluminum alloy. Take care not to overheat it. Watch the

heating temperature using a thermopaint, or heat crayon

(see page 2-31).

NOTE: Welded parts that can be partially cut and replaced are restricted to those listed in this manual (see section 4).

6. Cut off and separate the damaged parts.

NOTE: When cutting the parts off, take special care

that you do not damage adjacent parts on the automo-

bile.

7. Mold the related parts.

8. Check the reshaped parts for cracks (see page 2-29).

9. Set and tack weld the replacement parts.

NOTE: Temporarily mount the related parts and check the clearance and level differences.

10. Weld the replacement parts. Welding methods (see section 2).

NOTE: Use of the positioning jig is recommended.

11. Check the welding sections for cracks (see page 2-29).

3. Check the original position using the body dimensional drawings (see section 6) and the positioning jigs

(see page 1-7).

4. Remove the parts that require replacement.

NOTE: The paint film, which is designed to prevent corrosion caused by moisture, is destroyed around the edges of the locations that have been repaired by welding. Therefore, in such places and especially in those areas that are not visible, apply another coat of the paint;

refer to the anti-corrosion painting manual. This operation is designed to maintain durability and quality (see section 7).

Preparation of Work

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Measurement (Excluding small damage)

Whenever possible, make judgements and conclusions based on measurement. Measure the wheel alignment (see page 1 -2) so as to prevent any future trouble like unsymmetrical wear of the tires or catching of the steering wheel.

If there are any deviations, use a tram tracking gauge and measure parts of the body.

If there is any twisting to the body, measure using a frame centering gauge.

When measuring body dimensions, use a universal tram gauge.

Positioning Jig

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Front under frame positioning jig Rear under frame positioning jig

Roof panel positioning jig set NSX-T (open top) only

4-14

4-61,

4-65, 4-68

4-10,

4-22, 4-31, 4-38, 4-50, 4-69, 84, 89

Aluminum Alloy Repair

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Safety Precautions

Precautions for Ensuring Safety:

1. Although aluminum is non-toxic, it is lightweight, so fine particles of metal given off by sanding operations tend to float in the air. It is therefore vital that operators protect their lungs and eyes from this dust.

2. Small pieces of aluminum alloy are spattered by MIG welding can be projected over considerable distance. It is therefore

important to provide protection not only for the welders operators themselves, but also for anyone in the surrounding areas.

3. The sparks generated from the arc during inert gas are welding are very bright and may hurt the eyes if viewed directly. A protective shield for the eyes must therefore be worn at all times when welding.

Use of protective gear to ensure safety:

Work overalls with long sleeves, a cap, and safety shoes must be worn at all times. Depending on the job to be done, protective goggles, gloves, ear plugs, and a dust-proof mask should also be worn (see page 2-7).

CAUTION:

• When aluminum alloys are heated, they melt without changing color.

Melting temperature

Aluminum alloys: Approx. 1184°F (640°C) (depends on alloy) Steel plate: Approx. 2732°F (1500°C)

• Aluminum alloys can be repaired in virtually the same way as steel sheets, but it is important to have a good grasp of their properties and be thoroughly familiar with their limitations.

• Aluminum alloys tend to overheat during sanding. When they overheat, the metal tends to flake and clog the filing surface of the sanding tool. If a tool with a clogged surface is used, it will leave scratches and marks on the base metal.

Welding Methods

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1. MIG (metal inert gas arc) welding

This type of welding uses consumable electrodes, with electrode wire serving as the electrode. Inert gas is passed through the torch and welding takes place when an arc is formed between the electrode wire and the base metal. The electrode wire is supplied automatically.

Although it is dependent on the proficiency of the welder himself, the minimum thickness of weldable aluminum alloy sheets has been 1. 6 mm (0. 06 in). In most cases the sheets used have been over 3 mm (0. 1 in) thick. More recently, welders have been developed for handling sheets with a thickness of 1 mm (0. 04 in) or less.

2. TIG (tungsten inert gas arc) welding

This type of welding uses non-consumable electrodes, with tungsten rods serving as the electrodes. Inert gas is passed through the torch, an arc is formed between the electrode and the base metal, and welding takes place when the heat from the arc melts the base metal and hand-held welding rod. the minimum thickness of aluminum alloy sheets which can be welded is about 0. 6 mm (0. 02 in), although this method is not suited to heat-treated alloys because there are many thermal

effects.

3. Carbon dioxide gas arc welding (metal active gas arc welding)

In place of the high-cost inert gas, carbon dioxide gas or carbon dioxide gas mixed with argon gas is employed as the shielding gas in the metal active gas arc welders often used today in body shops. Carbon dioxide gas is not an inert gas in the full sense of the term so these welders are known by the acronym of "MAG" (metal active gas), rather than "MIG. "

4. Gas (oxygen, acetylene) welding

Welding or brazing work must not be undertaken using these gases.

Since it is hard to concentrate the heat at the welding point, the thermal effects extend to the surrounding area and the

strength of the aluminum alloy is reduced. Neither must gas welding be used for brazing since joint strength is too low.

NOTE: Gas welders are used for heating work when aluminum alloys are shaped. (It is necessary to control the upper limit temperature. )

5. Spot welding

Aluminum alloys cannot be welded using the conventional spot welders which are used in body shops.

The capabilities of spot welders for steel plate are not sufficient for aluminum alloys which have high thermal conductivity.

No matter how long the welding current is allowed to run, the heat escapes to the surrounding areas and the base metal does not melt, making welding impossible. It requires a very high current of several tens of thousands of amperes and high pressure to spot-weld an aluminum alloy.

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Welding Methods (cont'd)

Comparison of spot welding for aluminum alloys and steel plate (one example)

NOTE:

• Welding conditions may induce changes in the spot welding current given in the comparison above.

• See page 2-10 for the re-bonding procedure applied when spot-welds on an aluminum alloy body are repaired. MIG welding is used.

• A person proficient at carbon dioxide gas arc welding who has an adequate understanding of the properties of aluminum alloys will be able to master the technique after practicing for a short while. Practice is important for increasing one's competence.

CAUTION:

• Aluminum alloys melt without changing color when heated.

• It is difficult to judge the melting point when an alloy is heated.

• Aluminum alloys have a coefficient of thermal expansion which is approximately double that of steel plate and a coefficient of contraction during solidification which is approximately 1. 5 times higher. They are therefore subject to strain more easily and welding cracks (bead cracks and crater cracks) develop.

• Cleaning the welding location greatly affects results. Although the oxide film is destroyed by the cleaning action, it is important for all dirt to be removed, along with any oil and grease, prior to the welding.

• Tools used for welding aluminum alloys must be kept completely separate from those used for steel plate.

• Use a stainless steel wire brush.

• Use sanding tools which have been reserved especially for use only with aluminum alloys. If the same tools are used for steel plate as well, iron deposits will remain on the surface of the aluminum alloy and contaminate welds. )

• Inert gas arc welding is a gas-shielded method and is therefore unfit for working in areas exposed to wind or breezes. It is important that the flow of the inert gas is not disturbed.

Welders

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Performance of Welders:

1. Output current: Approx. 200 A at maximum output

2. Electrode wire diameter: Approx. 0. 8~-1. 2 mm (0. 031 (A5356WY) ~0.05 in)

3. Shielding Gas: 100% Argon

• It is an added convenience if the welder can be set to seam, stitch and spot modes.

• A welder which can be used for both aluminum alloy MIG welding and steel plate carbon dioxide gas arc welding simply by changing some parts is economical and efficient.

NOTE: Follow the manufacturers' instruction.

Aluminum Alloy Repair

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Filler Metals

When "filler metal" is mentioned in this text, it refers to welding rods for TIG welding and to electrode wire for MIG welding.

The selection of the filler metal affects the following items relating to the state of the welded joints:

Flaws in joints (bead cracks)

Strength of joints

Toughness of joints (tenacity)

Resistance of joints to corrosion

is the filler metal best suited to aluminum alloys in the 5000 and 6000 series which are used for HONDA

aluminum alloy bodies.

Filler metal storage

Proper storage of filler metals is important for best welding results.

NOTE:

• Store filler metals where they will not become dirty or scratched and where they will be free from contact with oils and greases.

• Use clean gloves when handling filler metals. Seal them in airtight vinyl bags, and store at a constant temperature in a location where they will be dry at all times. Before sealing the electrode wire, make sure that it is wound properly on its spool.

• Take steps to ensure that the seal cover is not opened until actual use.

Examples of Repair Tools

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Aluminum Alloy Repair

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Examples of Repair Tools (cont'd)

NOTE: Use a stainless steel wire brush and sanding tools reserved especially for aluminum alloys. Do not use the same tools

for steel sheet.

Grain size for sanding/processing tools and jobs performed.

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NOTE:

• Use a low-speed disc grinder or disc sander.

• If a low-speed air-powered disc grinder is not available, attach an air control valve to reduce grinder speed.

• A double-action sander may also be used.

Cleaning-oxide film removal:

Clean the welding locations throughly (both front and back surfaces).

• Use a wax and grease remover to clean off any dirt, oil or grease.

• Use a disc sander and stainless steel wire brush to remove paint and oxide films. Use a #80 sanding disc.

NOTE: Do not allow the sanding disc of the disc sander to become clogged. If the disc sander is pressed excessively hard, it will overheat due to friction and the aluminum alloy will tend to peel off, clogging the disc. The alloy surface will be scraped and scored if a clogged disc is used.

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MIG Welding Conditions

MIG welding can be performed under virtually the same conditions as for the carbon dioxide gas arc welding of steel plate mentioned previously. The differences are outlined below.

The factors which affect deposition at the welding location and serve as the welding conditions for carbon dioxide gas arc welding

of steel plates are:

• Welding current,

• Welding voltage (automatically adjusted for HTP MAXI MIG),

• Electrode wire speed,

• Distance between contact tip and base metal,

• Gun angle,

• Gun feed speed,

• Volume of shielding gas.

NOTE:

Distance between contact

tip and

base

metal: 8~15

(0.3~0.6

in).

Arc generation

As with steel-plate welding, an arc is generated and welding starts once the torch switch is thrown.

• Welding startup is impaired if the electrode wire extends too far out or if the end is spherical. In such cases, cut off the end of the wire with a pair of wire cutters.

CAUTION:

• The torch switch must not be thrown with the electrode wire in contact with the base metal.

• When cutting the end of the electrode wire, point the torch downward and cut near ground level to

protect the eyes from the cut end.

Sound of arc when welding under proper conditions:

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• With aluminum alloy MIG welding, there is a quiet and continuous humming sound similar to that heard during carbon dioxide gas arc welding.

• A small amount of soot is formed along the bead during MIG welding. This is caused by magnesium contained in the electrode wires.

1. Differences in welding conditions

When comparing the welding of aluminum alloys and steel plate using the same welder, the thickness range of plates which can be welded is less for aluminum alloys. In other words, the welder setting conditions must be adjusted more finely for welding aluminum alloys.

-1. Welding current, electrode wire speed Under the same welding current conditions, the electrode wire for aluminum alloys needs to be fed faster than that for steel plates.

— 2. Distance between contact tip and base metal

As for steel plate welding, the distance ranges from 8~15 mm (0.3~0.6 in). The gas shielding effect is enhanced by

positioning the gun closer to the surface.

-3. Gun angle The gun is held perpendicular to the welding surface. It is tilted at a 5~15°angle in the direction of the welding advance. Compared with steel plate welding, the gun angle is slightly more vertical.

— 4 Direction of gun advance

Either a straight sequence or back-step can be used when for welding steel sheets. With aluminum alloys, however, only

the forehand welding method is used.

-5. Gun travel speed Welding of aluminum alloys progresses at a much faster rate than for steel plate. The speed increases as the welding

progresses.

-6. Volume of shielding gas About 50% more gas is required than for steel sheet welding.

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MIG Welding Conditions (cont'd)

2. Nozzle and contact tip

Compared with the carbon dioxide arc welding of steel plates, spattering adheres more readily at the end of the nozzle and the contact tip.

• Adhesion of spattering can be reduced by using an anti-spatter compound. This makes it easier to remove spatter as well.

• The nozzle and contact tip are subjected to greater wear than with steel plate welding.

3. Electrode wire setting

Since the cable inner liner is made of teflon, be sure not to mark or scratch it.

• Use sandpaper to smooth the edge of the end of the electrode wire before feeding it through by hand.

4. Adjustment of electrode wire drive roller tension

Tension is adjusted to a setting less than that for steel plate welding. When the electrode wire is held lightly at the contact tip area and the torch switch is on, the wire is set so that it will slip in the drive roller area. If the tension is set too high, the

aluminum alloy electrode wire will be twisted. If it is set too low, the wire speed will not be constant.

NOTE:

• The tools used for aluminum alloy welding should be kept completely separate from those used for steel plate.

• Use a stainless steel wire brush.

• Use sanding tools which have been reserved especially for use with aluminum alloys, (If the same tools are used for steel plate as well, iron deposits will remain on the surface of the aluminum alloy contaminating the welding locations.)

• Proper storage of electrode wire is important for best welding results.

• Store electrode wires where they will not become dirty or scratched and where they will be free from contact with oils and greases.

• When electrode wire is being used, ensure that it is wound properly on its spool. Use clean gloves to seal wire in airtight

vinyl bags and store at a constant temperature in a location where it will be dry at all times.

• Take steps to ensure that the covers sealing electrode wire containers are not opened until actual use.

Plug Welding Procedures

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When removing or replacing plates bonded by spot welding, drill through the spot weld nugget and remove. The combinations shown in the figures below apply when plates are to be welded together. Drill the hole when the plates have been removed or drill the prepared hole, and proceed with plug welding.

1. Plate combinations and prepared holes Diameter of drill (spot cutter) when removing plates: 10 mm (3/8") Drill the hole in the new part. Drill diameter: 8~10 mm (5/16~3/8")

2. Adherence Where the plug welding is to be performed, the aluminum alloy plates must adhere together firmly, otherwise the welding will

be defective.

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Plug Welding Procedures (cont'd)

3. Cleaning and sanding

• Use a wax and grease remover to clean off any dirt, oil or grease prior to welding.

• If the aluminum alloy surface is coated with a paint film, use a disc sander and #80 sanding disc to remove the paint.

• Use a stainless steel wire brush to burnish the bare surface of the aluminum alloy immediately before the welding. NOTE: Use a stainless steel wire brush to burnish the bare surface of the aluminum alloy immediately before welding.

Cleaning range

Unit: mm (in)

When drilling a single-layer hole in two stacked plates:

Sand the top and bottom surfaces of the top plate and the welding surface of the bottom plate.

Oxide film removal by sanding

Remove oxide film by sanding.

Prepared hole.

When a hole is to be made through two stacked plates:

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Sand the top and bottom surfaces of both the top and bottom plates.

When a hole is to be made through three stacked plates:

Range of oxide film removal by sanding.

Sand both surfaces of the top, middle and bottom plates as

shown to remove oxide film.

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Plug Welding Procedures (cont'd)

4. Welding Prepared hole diameter: 10 mm (0.4 in)

Plug welding starts from the outside of all weld zones (outside start).

As shown in the figure, outside start welding commences at a position approximately 15 mm (0.6 in) from the weld zone.

Advantages of outside start

• Penetration is enhanced by the preheating effect accompanying the outside start.

• The initial penetration area is clearly visible is the light given off by the arc and working efficiency is improved.

• Outside start provides preheating to safeguard the aluminum alloy from inadequate initial penetration.

NOTE: Maintain a stable posture so that the torch does not move around but is held firmly and so that the weld zone is clearly

visible.

When drilling a single-layer hole in two stacked plates:

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Proceed with welding while aiming at the edge of the hole

where the top and bottom plates meet.

NOTE: Melting of 1/3 to 2/3 of the bottom plate is the adequate for the weld.

With a hole through two stacked plates:

• Proceed with welding while closely observing the melting condition of the weld zone.

• Until the operator is experienced in welding, take care not to increase the distance between the torch contact tip and base metal.

• Ensure adequate penetration as far as the bottom plate. The reverse side bead on the bottom plate may protrude

in the process. Keep the protrusion to a minimum.

(1) First, proceed from the top.

Proceed with welding while aiming at the joint where the top and bottom plates meet.

With a hole through three stacked plates:

Proceed with welding while aiming at the joint where the

middle and bottom plates meet.

• The plug hole is filled after welding to a distance equivalent to about one and half times the entire circumference.

• The plug hole is filled after welding to a distance equivalent to about twice the entire circumference.

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Plug Welding Procedures (cont'd)

(2) Use a disc grinder or disc sander to grind down the area

where the bead on the reverse side protrudes until it is flush with the surface of the bottom plate.

(3) Use a stainless steel wire brush to burnish the surface

where the bead is ground down.

(4) Use an outside start to weld the bottom plate where the

bead is ground down.

(5) When welding the bottom surface, position the torch

perpendicularly and weld around the edge of the plug hole.

Butt Welding Procedures

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Reduce the clearance as shown in the figure below for butt welding thin plates or sheets. If the clearance is too wide, welding

should be performed in the stitch mode.

1. Edge preparation Weld with a square edge without special preparation.

• Use a smooth-cut file to bring the the edge preparation surface to a smooth finish.

Proceed with V-shaped edge preparation.

• Edge preparation is required for butt welding thick plates, as shown.

• Use a disc grinder and file (rough-cut or vixen file) for edge preparation.

• Use a disc sander with #80 sanding disc and a file (smooth-cut) to finish the prepared area.

• Reverse side beads often occur because of edge preparation in the above figure.

2. Cleaning and sanding Use a wax and grease remover to clean off any dirt, oil or grease prior to welding. If the aluminum alloy surface is coated with a paint film, use disc sander and #80 sanding disc to remove the paint. NOTE: Use a stainless steel wire brush to brush the bare surface of the aluminum alloy. Do this on both the top and bottom surfaces.

Sanding range

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Butt Welding Procedures (cont'd)

Sanding range

For V-shaped edge preparation:

Sand the top to a width approximately 3 times the width of the edge and the bottom to a width approximately equivalent to the edge.

NOTE: Also sand the edge preparation area.

3. Tack Welding Prior to finish welding, carry out tack welding to prevent strain and enhance joint precision. Weld the plates at several

points with short beads.

NOTE: Use a stainless steel wire brush to clean the tack weld zones prior to finish welding.

• The thinner the sheet or plate, the shorter the tack welding pitch and bead.

• Avoid tack welding the ends and corners of the base metal.

• Since the beads left by tack welding are not ground down afterward, this process should be carried out with the same precision as finish welding.

4. Main welding

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Maintain a stable posture so that the gun does not move around but is held firmly. The weld zone is clearly visible. Maintain the proper distance between the gun contact tip and the base metal, and maintain the proper gun angle. Adjust

the gun feed speed while observing penetration.

NOTE:

• Aluminum alloys are welded at a higher gun feed speed than steel plate.

• Use the forehand welding sequence for the gun advance direction in order to minimize the formation of black soot.

• Until the operator is experienced in welding, take care not to increase the distance between the torch contact tip and the base metal.

• When welding multiple layers of a thick material, brush the surface of the welded area thoroughly using a stainless steel wire brush after each pass.

5. Crater treatment

Craters may form when the welding bead is completed. They should be filled properly to avoid defects.

There are two ways of treating craters. Either stop the gun and fill the crater without switching off the arc suddenly

when

the

welding

bead

completed,

alternatively,

switch

the arc and

then

back

again

fill

the

crater.

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Butt welding Procedures (cont'd)

6. How to weld without inducing strain

Tremendous strain results if the base metal is overheated during MIG welding.

• When many welding joints have been created, proceed to weld from a location with a minimal degree of freedom. Normally, welding proceeds from the center of the area or center of the joints to the outside.

• In direct proportion to the thickness of the plates, do not conduct lengthy welding operations at one time. Instead, divide

the job up into shorter operations, as shown in the figure below.

Preventing strain by sequencing welding work:

Welding procedure

• When an operator is experienced, the strain can be reduced by increasing the gun feed speed at higher power settings (current). This method reduces the amount of heat transmitted to the base metal.

• In the case of thin plates where there is a danger of melt-down, do not weld continuously without stopping but weld short sections at a time. If the welder is provided with a stitch mode, set to this mode and perform stitch welding.

Butt weld zone defects:

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The table below shows possible weld zone defects and their causes. Care must be taken to ensure that none of these defects occur. If a defect does develop, pinpoint the causes and consider the appropriate countermeasure, change the work method, and proceed in a way which will produce stable welding results.

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Butt welding Procedures (cont'd)

+ 208 hidden pages