Beginning Metal Repair

Transcription

1 Beginning Metal Repair

2 Herb Spenner! Background Introduc3on! Electrical Engineer Purdue, A&P Gavilan College! Gavilan Avia3on Technology Instructor FAA Airframe and Power (A&P) mechanics program A&P with IA (Inspec3on Authoriza3on) Teach General & Airframe classes Web based informa3on! hop://hhh.gavilan.edu/hspenner/beginmetal/

3 Class s Star3ng Idea

4 Rules & Safety Topics Basic metal proper3es CuSng Cleaning Welding Drilling & tapping holes Fasteners Home welder

5 Projects Drilling and Tapping! CuSng bar stock! Drilling! Tapping! Bolt extrac3on! Thread repair (Heli-Coil )

6 Projects Sheet Metal Welding! CuSng! Cleaning! Tack! BuO! RoseOe! Flanging! Finishing

7 Rolling Cart! CuSng Projects! Cleaning! FiSng! Welding! Joint reinforcement! Finishing

8 Safety First! Rules and Safety! Get instruc3on on equipment! Eye protec3on and gloves required for all power tools! Welding only with a helmet, jacket and gloves Proper ASre! No loose fisng cloths! Natural fiber cloths Nylon and Polyester will burn! Long pants - blue jeans! Closed toed shoes! No loose jewelry

9 Rules and Safety Act Professional! Respect the facili3es Don t touch anything in a cabinet without asking Don t touch any of the students tools Return all Gavilan tools to their proper place! Respect your colleagues No ea3ng or smoking allowed in classroom or lab! Drinks are acceptable Cleanup a_er yourself

10 Ferrous Metals Ferrous metal is one that contains iron Pure iron is too so_ for most uses! Add carbon to iron and you get steel SAE - Society of Automo3ve Engineers! SAE four-digit numbering system for iden3fying steel Hard steel, such as drill bits and taps, break very easily Heat treated, hardened & coated metals are not welded

11 CRES Corrosion Resistant steel Stainless steel 10+% of chromium 200 thru 400 series Usually not as strong as carbon steel Usually non-magne3c Difficult to weld

12 Aluminum Alloys So_, lighter and more expensive than steel Aluminum alloy four-digit iden3fica3on system:! First digit - Alloy type! Second digit - Modifica3on of alloy Many of the stronger alloys corrode and can t be welded Work hardens and fails drama3cally Steel fasteners will cause aluminum to corrode! Paint aluminum or use sacrificial washer

13 Alloys! Beryllium Copper Alloys! Zinc makes brass! Tin makes bronze! Aluminum! Manganese Corrosion resistant Becomes briole when work hardened Can t be welded! Braze or solder

14 Metal CuSng Saws with teeth use oil Hack saw! More teeth per inch (TPI) the finer the cuoer! If careful, can be very accurate! Invest in a ridge frame Saber saw Scrolling saw Band saw Shears Plasma cusng

15 Metal CuSng Abrasive chop saw! Good for bar stock! Rough finish! Hard to get accurate! No oil Angle grinder! CuSng wheel abrasive Wears quickly! Grinding disk - shaping! Sanding disk - shaping Belt sander - shaping

16 Cleaning Metal All corrosion must be removed before welding or paint Steel corrosion removal! Scotch-Brite! Sand paper! File! Grinder! Wire brush or wheel! Phosphoric acid e.g. Naval jelly

17 Cleaning Metal Aluminum corrosion removal! Scotch-Brite! Very fine sand paper! Stain steel wire brush not used on steel! Phosphoric acid wash Copper! Scotch-Brite! Sand paper! File! Grinder! Wire brush or wheel

18 Cleaning Metal Oil must be removed before welding or pain3ng! Denatured alcohol! Acetone fingernail polish remover Water test water will form a film on clean metal! If the water film breaks, the surface is not clean

19 Welding Puddle

20 Welding Welding a process that joins metal by mel3ng or hammering the work pieces un3l they are united together.! Base metal must be melted! Process must protect molten metal from atmosphere! Material (filler) is added to joint! Filler material must match base metal! Process must control the amount of heat and the rate that filler is added

21 Weld Joints

22 Bead

23 Welding Gas welding The use of oxygen and acetylene (oxy-acetylene) to create a flame that melts the metal to be welded! Burning process protects metal! Uses filler rods! Medium hard to learn! Portable! Dirty! Easy to add heat trea3ng and cusng op3ons

24 Welding Shielded Metal Arc Welding (SMAW) s3ck! Arc welding process that uses a consumable fluxcoated electrode! Flux melts and coats molten metal Forms a glass like cover must be remove Helps remove impuri3es! Easy to learn! Simple equipment! Crude results! Can be used outside! Video

25 Welding Gas Tungsten Arc Welding (GTAW) an arc welding process that uses a non-consumable tungsten electrode to produce the heat for the weld.! TIG Tungsten Inert Gas! Shielding gas usually is argon or helium! Similar to Gas Welding, except uses a electric arc! Very clean/very sensi3ve to dirt! Can t be used in windy condi3ons! Very hard to learn

26

27 Welding Gas Metal Arc Welding (GMAW) MIG - a method of welding in which the filler metal wire supplies the electric current to maintain the arc, which is shielded from the surrounding air by an inert gas, usually argon or carbon dioxide (CO 2 )! Filler is automa3cally fed from reel of wire! Easy to learn - one handed applica3on! Fast! Can t be used in windy condi3ons! Dirty and splaoers! Difficult to determine the quality of the weld

28 Welding Video

29 Welding Video 1 Video 2

30 Welding Flux Core Combina3on of s3ck and MIG welding! Uses a MIG welding machine! Welding wire is hollow with flux inside! No shielding gas! Easy to learn! Can be used outside! Dirty

31 Welding Spot welding Uses electric current to fuse two pieces of sheet metal together! No filler material! Clean! Easy to use! Extensively used in the automo3ve industry! Video

32 Weld Joints

33 Weld Joints

34 Tack Weld

35 Tack Weld

36 RoseOe Weld Video

37 Drill Bits Sizes available in fraction of an inch, metric and numbered Soft metals high speed and light pressure Hard metals low speed and higher pressure Reduce speed a bit size increases Use oil for cleaning chips and cooling

38 Tap and Die Die Tap

39 Threads! UNF fine Tap and Die! UNC course! Na3onal Taper Pipe (NTP) Tapered to seal fluids! Rolled and cut Rolled is stronger Use matching drill size Use cusng oil and/or grease (catch shavings) 1/2 turn forward and then backup Straight and slow

40 Tap

41 Plain Washers Provides a smooth bearing surface Protects surface from galling & corrosion! Must be used when using a locking washers Should be used under every bolt head and nut When using lock washer, the order should be:! Bolt! Plain washer! Ma3ng surface! Plain washer! Lock washer! Nut

42 Home Welder Invest in a good helmet MIG best op3on Be care of MIG core flux welders Be care full of combo welders inexpensive ones may have to many compromises! e.g. starter circuits! May need op3onal equipment Find one with infinite (smooth) adjustments Is 110 volt enough? ¼ max welding Cart with good wheels

43 Longevity MIG 140