ok so im kinda new at metal work and really want to learn how to just fabricate stuff when i need to, so i decided after seeing the article in SR that i was going to make my self a set of aluminum aircraft seats. keep in mind that aside form a little welding and some basic bracket making my fab experience is kind of limited. so i make patterns and get all the shapes ui want cut out and then i go to shrink the 90* pieces that hold the side and bottom together, and its tough. i have been using some practice 5052 .063 aluminum with my hand shrinker and the curve doesn't seem to want to go into it. my question is(finally) can i anneal the 90* piece and then shrink it? annealing would soften it a bit and working it hardens it right? let me know if i'm way off base or this sounds ok, any tips are appreciated!! oh and if anyone knows where to get "military style p shaped extruded aluminum edging" for the top edge, i know there are a couple people who would like to know where to get it thanks matt
the shrinkers only pull a little at a time. You may be better off pie cutting it and welding it to form a tight turn like that.
i thought of that but: i can't weld aluminum, or should i say haven't tried, and im trying to go for more of an original style of building them with only rivets. the eastwood catalog says there shrinker will do a 3 inch radius curve, mine are the same style just older(and free!) and my radius is bigger than that. i will keep that in mind if it comes to that though thanks!
I did a bomber seat out of stainless and my shrinker stretcher did fine. It will take multiple p***es each p*** will be faster since you are curving a piece that already has a curve to it. You will get best results by just shrinking the outer edge of the metal. A lot of people will stick the flange as far into the shrinker as it will go. You only need work the outer edge as this is where the most shrinking is required. Here is a link to the seat I did. Good luck!! http://www.jalopyjournal.com/forum/showthread.php?t=141891
i've been doing p*** after p***, and it is curveing just s l o w l y. so what you saying is just knuckle down and shrink with heuvos(sp?) thanks matt yours look kick *** by the way i hope mine turn out that good, i know i can't bead roll that well so i might not even bead these, just dimple die the sides
If you want to anneal, light your torch like normal them turn the oxygen down til' you get those little black floating "thingies", Color up you panel with soot until it has a nice even and solid coat. The piece might wave a little back and forth don't panic that's normal. Last turn up your air a bit and burn off the "guide" coat of black soot. shape as desired. repeat heating if needed. Oh practice on s****s, that's always a good Idea.
After a couple of p***es you should start to see some progress. You could try annealing the aluminum. I don't think it would hurt anything. You should be able to anneal it with a propane torch. Draw a line on it with a sharpie marker then heat it with a propane torch until the line disappears.
Questions?... What kind of shrinker are you using? How many p***es are you making through the shrinking jaws with the piece you are trying to shrink? If you are using one of those **** shrinkers from Eastwood check and make sure that jaws are actually pulling togather when the lever goes down. Sometimes those things jam up and no matter how hard you push on the lever its doesnt do ****!...In fact those machines even when they are working there best don't really give you a solid pull on the metal. I really doubt you are work hardenening the metal....You have to really beat up Non-Heat treated Aluminum to get it to the point where its needing to be annealed. But as ****ty at those shrinkers work it might not hurt to aneal it alittle. Don't go nuts though. small thin parts like that will melt quick! Also remove the screws and Flip the wire clips off the jaws and take them off the machine and make sure there is nothing jamming it up. chips of dust? When you put them back togather put some anti-sieze on the "angled" contact surface where the jaw slides on the machine..Also when you put the clips back on make sure they are pulling the jaws back apart....the clips are also your return springs so you might have to bend them alittle to make sure they pull back....I bet this is the problem...When you are pushing the lever down the jaws are already togather..and it does nothing!.............This will help make things work semi-better... Hope it helps........
try some 3003 H14 - you will have better luck. If you want to aneal - dust it with carbon from a O&A torch ( acetone burning only ) And burn carbon soot off with torch ( O&A ) burning. This aneal deal will make 3003 H14 Dead soft & very formable and Much easyer to shrink.
Jesse makes a good point.....I had this trouble with mine. A little lube on the jaws will make all the difference in the world.
I don't know if this will help,.. but a trick I learned from a old friend (Frank Mack) on annealing aluminum,... he would use a large rosebud tip on this torch,.... sprinkle sawdust on the the top of the aluminum, "and just heat it up from underneath until the sawdust just started to toast up, and it's done" in the words of Frank,... or else you could use the back of a wood kitchen match,... with the back of the match stick, you would draw it along the top of the aluminum as you were heating it from the bottom,.. "when it left a mark like a pencil on paper",... it was done.... ( of course it had to slow cool ) He was doing this in the 40's.
Hey, I don't beleve that you will have much luck with annealing 5052 aluminum given it's alloy content. It would be a good choice for a part that doesn't have much shape, i.e. low crown. For a part that will require alot of shape go for 3003 H14. this alloy is hand shapeable, shrinkable & gas weldable. S****ey Devils C.c.
<TABLE cellSpacing=0 cellPadding=3 width=570 border=0><TBODY><TR vAlign=top><TD colSpan=5> </TD></TR><TR vAlign=top><TD colSpan=5>Anneal at 650 F and air cool. Use a 650 F Tempilstik Crayon(about $12.00) to ensure even temp while annealing. </TD></TR></TBODY></TABLE>
is the dissimiler metal going to cause a corrosion problem? they will both be aluminum i understand but i don want corrosion coming out from behind my rivets and stuff thanks for all the replies i will try to dis***emble the tool and lube everything, but the jaws are doing the proper motion when i use the tool. thanks again matt
i agree with jesse, first look to make sure the shrinker is working right. mine had the holder bent and needed a touch of white grease on the ramps before it would work right. also make sure you buy the one made in the usa, the chinese one is even worse. gary
Ok I'm in the market for a good shrinker stretcher.. i used Eastwoods before and had success making a new trunk lip for the rubber seals..but those were tiny pieces and actually bent fairly easy..but on bigger stuff It was always a fight to get it to bend...So what is a good set to buy?
Get a better shrinker, aluminum will pull right around. I never have to make more than one p*** unless I screw up.
You wont have any dissimilar metal problems with 3003 and 5052.Shrink at the edge like Sealed Power said then shrink the rest of the flange to remove the waves.Use zinc chromate primer on parts that will be riveted together for additional corrosion protection,you can get it from any of the aircraft supply houses.
The edge needs to shrink the most. Instead of putting the Aluminum into the shrinker as far as it will go,start with the first 3/8". Work along the curve,then go in deeper, and work your way back.Now do just the edge again.
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