hotiron Posted February 22, 2009 Share Posted February 22, 2009 (edited) Hello. I'm new here so bare with me. I'm a welder by trade, been one for 5 years now and have been working with metal since I was a little boy. (My father started out as a tin-knocker, now boilermaker) I need a little help from some fellows with definitive knowledge who would know what I'll need to do and how. How should I go about this? What process, etc. You see, I'm interested in slightly modifying a front Model T Ford leaf spring at either end of itself, at the spring eyes. What I need to do specifically (bare with me as this is not the easiest thing to explain on a keyboard! ha!) is to bend the first three leafs, starting with the main leaf, forward at the ends so that the first 4-5 inches of either end is bent forward. Level, and even. No twist, keeping each end level to where it was originally, horizontally. I had read in an old Model T speed manual from the 1920s, that after heating a spring and working the ends (either dropping it so it sits lower, etc.) to pour oil on it to cool it. It read that doing so would allow the spring to keep almost all, if not "all" of its original spring characteristics. Is this part of the process used? This is for a 1920s era dirt track racing car I'm in the process of building right now. I know this exact thing has been done successfully several times because a man by the name of Johnny Gerber who lived and raced in the 1920s did this very modification to his front springs as he had a very good friend who was a blacksmith. Not one spring ever broke, but were replaced after one or two mix ups at the tracks after others had spun out and caused John to crash into the guard rails. The tools at my disposal for this are: - Cutting torch with a rosebud end (or cutting tip, whichever would be better) - Anvil - Large vice - various handtools, hammers, etc. - will power and an open ear! I'm going to try and add some photos of the spring that is still on his old chassis at the National Sprint Car hall of Fame. Thanks a million fellas! (Photos of Johnny Gerber's front Model T spring) Edited February 22, 2009 by hotiron Quote Link to comment Share on other sites More sharing options...
saintjohnbarleycorn Posted February 23, 2009 Share Posted February 23, 2009 you could make a jig to hold everything straight while you bend it. The quenching and all is beyond me, but there lots of people here who know how. bending it would be the easy part I would guess, the tempering might be a bit tricky. good luck. Quote Link to comment Share on other sites More sharing options...
Finnr Posted February 23, 2009 Share Posted February 23, 2009 Your best bet is to take the spring unit to a good suspension shop. They have the equipment to properly heat treat the springs after reshaping. Finnr Quote Link to comment Share on other sites More sharing options...
hotiron Posted February 23, 2009 Author Share Posted February 23, 2009 (edited) Your best bet is to take the spring unit to a good suspension shop. They have the equipment to properly heat treat the springs after reshaping. Finnr Unfortunate, but quite true, I do not have a good suspension shop anywhere near me. The one that used to make their own springs now doesn't do anything but order in pre-made springs. They are of absolutely no help and do not want to be bothered beyond that. Another place never did any work like that even though they are a "spring shop". Hence the reason I'm looking to do it myself. Other than that, I'm not looking to order something specially made for me. Edited February 23, 2009 by hotiron Quote Link to comment Share on other sites More sharing options...
Paul B Posted February 23, 2009 Share Posted February 23, 2009 I think Fallsway Spring in Baltimore may be able to help you. Quote Link to comment Share on other sites More sharing options...
orgtwister Posted February 23, 2009 Share Posted February 23, 2009 hot iron were in pa are you its a big place if your on the east side there at least 2 spring shops in jersey i know of there mercer springs in trenton and r&h in wall across from wall stadium in my opion if your really going to race this vehicale i my self would let the pros doit cause as i'm almost 40 now and have learned to value my life more now if i was 17 again well lets just say im no sure how i'm alive now Quote Link to comment Share on other sites More sharing options...
hotiron Posted February 23, 2009 Author Share Posted February 23, 2009 (edited) So, it can be done, but should I then assume no one here has yet to work on auto leaf springs then? Obviously, I could have just strolled through the internet seeking out a shop in my surrounding area to do the work for me. I know this, but if I chose that route, I would not have asked my question. I chose not the easy route, but one where I might learn how, rather than pay another to do so. I understand my abilities and know my limits of course. The fact is, I'm not looking to take on something I may as well regard as rocket science if its that seemingly foreign to me, and I end up questioning my chances for success. That would be both a waste of time, and money spent on a new spring I already have now. But, I'd never had asked my initial question if I thought it were something that foreign to me or something I thought I'd fail at or take a wild card chance at. So, I can understand if no one has had any experience in doing the job of making leaf springs or working with them in the manner I'm looking to learn,etc. that's ok. I'm just looking for definitive answers to my question that's really all I'm after. If I do choose to go the route of having another bend the springs, I'm more than sure that many fellows on here are willing to help me find a suitable shop or person, and I'll be full of thanks you's for that if I choose that route, trust me. For now though I'd like to see where this takes me. Thanks guys. Edited February 23, 2009 by hotiron Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted February 23, 2009 Share Posted February 23, 2009 find a sword maker near you, as we have the equipment to heat treat those larger things :) Quote Link to comment Share on other sites More sharing options...
Quang0 Posted February 23, 2009 Share Posted February 23, 2009 G'day Hotiron, As some of the guys said, the heat treatment of springs is pretty critical and without the right equipment you're probably going to get more problems down the track. The localized heating (with oxy etc) of the spring will remove the temper from a significant proportion of the spring, thus requiring re hardening and tempering of the entire thing. There are (dodgey) ways of keeping the spring from losing its temper, but then you run the risk of having a different temper through the spring when you re-heat treat the bit you bend. If the only gear you have access to is a gas axe and some quenching oil, then forget about it. I have heat treated a few smaller springs (2' x 3" x 1/2") using a coke forge, but it's tough going to get an even heat, you really need a good size gas or oil furnace. My two cents. Paul Quote Link to comment Share on other sites More sharing options...
hotiron Posted February 23, 2009 Author Share Posted February 23, 2009 find a sword maker near you, as we have the equipment to heat treat those larger things I wouldn't know where to start! LOL! :o Quote Link to comment Share on other sites More sharing options...
NateDJ Posted February 23, 2009 Share Posted February 23, 2009 Basically the problem you will have is the heat treating part. You will have to evenly heat and oil quench the entire piece at the same time. The heat treat specifics are ones that are dependent on the type of steel and your desired temper of the steel. As Steve said, you will do well to find a decent sword maker who should have the proper equipment and a far better understanding of heat treating steal to desired temper than I. Quote Link to comment Share on other sites More sharing options...
hotiron Posted February 23, 2009 Author Share Posted February 23, 2009 (edited) G'day Hotiron, As some of the guys said, the heat treatment of springs is pretty critical and without the right equipment you're probably going to get more problems down the track. The localized heating (with oxy etc) of the spring will remove the temper from a significant proportion of the spring, thus requiring re hardening and tempering of the entire thing. There are (dodgey) ways of keeping the spring from losing its temper, but then you run the risk of having a different temper through the spring when you re-heat treat the bit you bend. If the only gear you have access to is a gas axe and some quenching oil, then forget about it. I have heat treated a few smaller springs (2' x 3" x 1/2") using a coke forge, but it's tough going to get an even heat, you really need a good size gas or oil furnace. My two cents. Paul Paul- Thank you for replying. Not to question your experience or knowledge, but I wonder then how so many fellas in the 1920s did it well in their home garages with the success they had if they did not know a blacksmoth in their area or simply did not have one?:confused: (Of course it was far more common to have people with small home forges in their backyards too!) I'd like to see it done personally, and of course, obviously do it myself, as I like to do as much work as I possibly can on the things I build, etc. In all honestly, I get flat out p***** if I can't do things myself. Not such as a thing of pride, so much as a thing of knowing and learning something that has become an almost lost art! Knowing I did it myself, is for me, very satisfying and important for me. Pride is simple, but it comes and goes,... knowing and learning, that's where its at!... at least for me!;) Edited February 23, 2009 by mod07 Language Quote Link to comment Share on other sites More sharing options...
Quang0 Posted February 23, 2009 Share Posted February 23, 2009 By all means question away, after all you don't know me from a bar of soap. As I said, there are ways to stop the rest of the spring losing it's temper (wrap it in cloth/leather and keep it wet and cool), and with as little heat as possible bend the spring and re-heat treat it. The material will stretch on the outside and upset on the inside, so you need to be mindful of buckling. There are semi accurate ways that backyarders can use to tell when a spring is at the right temper (using a piece of hickory for example) and with careful heating of the leaf, it is possible to get it to a reasonably even temper. The last thing yu want to do is make it too hard and have it snap. You probably know already, but you need to do each leaf separately. Paul Quote Link to comment Share on other sites More sharing options...
hotiron Posted February 23, 2009 Author Share Posted February 23, 2009 By all means question away, after all you don't know me from a bar of soap. As I said, there are ways to stop the rest of the spring losing it's temper (wrap it in cloth/leather and keep it wet and cool), and with as little heat as possible bend the spring and re-heat treat it. The material will stretch on the outside and upset on the inside, so you need to be mindful of buckling. There are semi accurate ways that backyarders can use to tell when a spring is at the right temper (using a piece of hickory for example) and with careful heating of the leaf, it is possible to get it to a reasonably even temper. The last thing yu want to do is make it too hard and have it snap. You probably know already, but you need to do each leaf separately. Paul Very interesting! Now you just need live down the street from me! HA! I appreciate your explanations, its nice to read and digest the how's and why's to this. Thank you. To what visual color do the springs need to be? Red, bright red, dull red,...? Is there a difference in oil used, is one more suited than another? If so, why? How much can the metal be worked untill it needs to be heated again, or is this just a matter of seeing it to know? How would hickory be used to test the temper of the steel? thank you. Quote Link to comment Share on other sites More sharing options...
NateDJ Posted February 23, 2009 Share Posted February 23, 2009 You could also build a ground forge using fire brick a good electric blower and long enough pipe with holes drilled along to build a long fire and supply air to it. Then use a barrel of oil to drop the spring into, you will have to keep the spring moving so need to hang it by something you can move around. Once it is cooled you will have to find a way to reheat the entire thing to the exact temperature you need so the spring will gain it's proper tension (temper) This is something that can be done in a fire brick forge but you need a way to measure and maintain exact temp and you need to know exactly what temp your steel needs to be tempered to and for how long. Where there is a will there is a way! Do you have a safe way to test the spring after you are finished? I would not wish to risk my life to a spring which was not tested but that is of course up to you. Quote Link to comment Share on other sites More sharing options...
Quang0 Posted February 23, 2009 Share Posted February 23, 2009 Spring steel is a pretty basic alloy, but an alloy none the less and as such you need to be careful when heating and forging, not too hot, and not too cold. Forging should be carried out at a medium orange colour and and should stop at red. The hardening temperature can be identified with a magnet (spring steel loses it magnetism when it reached the hardening temp (austenite)) and the temper should be done to a blue colour, and can be identified by running a slither of hickory along the heated part, the hickory goes very "slippery" on the steel at the correct temp. If you nave no experience in HT, i suggest you get a piece of scrap spring and do some testing before launching into the project. Paul Quote Link to comment Share on other sites More sharing options...
hotiron Posted February 23, 2009 Author Share Posted February 23, 2009 (edited) Hmmm,.... building a ground forge. Yep, I was afraid it would come to that. As I read your suggestions I remebered reading old articles in 1930s Popular science magazines I've seen through the years. That would be the way to go, no doubt about it! Well, I'm seeing this as something I could certainly learn and do myself, but the materials I have and limited space is going to severly hinder me from performing this task correctly with sucess in the end, I do believe. Well, sadly this thread will probably be short lived. I'd still like to go about this myself, maybe in the near future! who knows, anything's possible. I sure wish some of you fellows lived closer! There's a lot of great wealth to learn! I'll be looking for another way to get this done, other than my own self. I might have to wait a bit till I move forwrd,.. we'll see. I wonder what it would run me to have a spring made or have one modified? I know a new spring is around $150,...so,..??? Thanks a million guys for taking the valued time to explain the ins and out of this to me. It has been much appreciated!! I look forward to talking with you all soon about this and other topics! Again, thanks guys. Edited February 23, 2009 by hotiron Quote Link to comment Share on other sites More sharing options...
dablacksmith Posted February 23, 2009 Share Posted February 23, 2009 what i would do is take your spring heat and modify ot to be exactly what you want then send it to a spring heat treater to have it re hardened and tempered! that way you will get the shape you want and it will be hardened and tempered in a safe manner! as far as what the old timers did that was in the days where seat belts were optional and a helmit was for wimps! they didnt worry about getting the right spring temper... also if you have to have a spring made if you already have the shape it will help as a pattern .. good luck! Quote Link to comment Share on other sites More sharing options...
48willys Posted February 23, 2009 Share Posted February 23, 2009 The one time I tried to temper a spring it didn't go too well,but that was only for a tractor seat.The first try it bent like a wet noodle,the second try it snapped.So you might wreck a spring tring to do it,you might want to ask what is cheeper ,a new spring or doing it right the first time.Just my .02 Quote Link to comment Share on other sites More sharing options...
Frosty Posted February 23, 2009 Share Posted February 23, 2009 The one question I haven't seen asked is are you wanting to modify the existing spring from the 20's or are you talking about making a new one? There is quite a bit of difference in the alloys. Also there's something to consider and that's the tendency of racers to NOT give up their secrets tricks. If the racer was reshaping his springs successfully and others were not then what are the chances he'd actually tell them how he did it? Simply heating and bending with a torch, then pouring oil over it is a pretty unreliable method, especially if an experienced smith were doing it for him. On the other hand it'd be a good tale to mislead the competition. Remember how many guys died racing cars in the 20's and that the racers in general were a LOT less concerned with safety. If you plan on taking it out on the track and value your life have it done professionally. If it's for display and you can be reasonably certain nobody else will take it out on the track have a lash at it yourself. Many years ago when I was making a bumper from 5160 the spring shop told me they heat treat this way. Bring it to bright red and water quench, then temper by bringing it to dull red and oil quench. Quenched horizontally in troughs. I hung out for an hour and then watched them heat treat a batch to get a handle on color and technique. It worked fine for the bumper on my pickup but I certainly wouldn't bet my life on it. If on the other hand you want to mess with a 1920's era spring good luck, I wouldn't touch it for love nor money. Frosty Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted February 23, 2009 Share Posted February 23, 2009 I'm really impressed that you even thought about stopping work on your project and spending several years just learning smithing so you could try to do your own work on the spring! Most people don't have the patience to spend the time learning when they want to try to copy the work of people with years of experience and experimentation and even shared knowledge behind them. Many people who may already know some of this stuff are afraid to answer in a forum like this due to liability issues. I myself would be happy to let you risk your own life; but would worry about the possibility of innocent lives being affected. Finally if you had asked this about 30 years ago I could have introduced you to an old retired smith in OKC who used to do such things way back when. We talked quite a bit while I was buying his old forges from him. Unfortunatly he would be the oldest man alive now if he was still living and so his knowledge is lost. Quote Link to comment Share on other sites More sharing options...
peacock Posted February 24, 2009 Share Posted February 24, 2009 If you can get to that car that you took the pic of you should mic the spring on each side right in the bent area. If it was bent hot the outside edge will be thinner than the inside edge. Back in the 70,s I worked in a race car chassis shop we modified leaf springs all the time. We did them all cold. I would bet that spring was also done cold. Most of the time we did them over the bore of a scrap motor block. If we wanted to change the arch we would lay the spring one leaf at a time over the bore and hit it with a 6# hammer. If we wanted more arch curve up less curve down. Edge wise is a little harder. You need to bolt some heavy blocks of steel down to the top of the block(use the head polt holes) leave only enough room to put the spring in on edge. the blocks need to be 1/2 the thickness of the spring width. with someone holding the sprig hit it HARD with a big sledge on the edge right over the bore and you can bend it, not easy but we did it. Kind of crazy the amount of work will go to win. good luck Phil Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted February 24, 2009 Share Posted February 24, 2009 I really REALLY advise against re-forging a spring cold. Not a good idea:o Quote Link to comment Share on other sites More sharing options...
peacock Posted February 24, 2009 Share Posted February 24, 2009 Steves last post is worth reading. I never said we were smart. We just did it. $150 for a spring won't get you in the door of the ER or funeral home. Thanks Steve. Phil Quote Link to comment Share on other sites More sharing options...
Awalker Posted February 24, 2009 Share Posted February 24, 2009 Now you know why the later rodders went to a suicide front spring perch. It does away with the need to have an oddly bent front spring. Remember also that with this type of spring set up, if your spring breaks you do the dreaded 65MPH pole vault. At least with a suicide spring perch, when the spring breaks the perch hits the axle. Quote Link to comment Share on other sites More sharing options...
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