Bridgestone Motorcycle Parts Discussion Board
General Category => General Discussion => Topic started by: moonpup on February 14, 2012, 03:11:41 PM
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Just noticed that my spare cover that I thought was in great shape with the exception of some corrosion, was actually in not so great shape. >:(
Luckily there was no hole punched through it but there is a dented area with some small cracks. I'm pretty sure there is no way that this can just be hammered back but can the area be heated and pressed back into shape? Are there other ways to tackle this and if so, can you share them with us/me? ;D
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Take it to a welder/fabricator. They will be able to weld a little aluminum to it and grind it down. That is nothing compared to mine. It should come out fine.
I just had some work done to mine and I will have to wait and see how it comes out. Scary looking.
If it does not work out for you, put your order in with Richard. NEVER KNOW WHEN YOUR GOING TO NEED ONE!!
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Thanks Harry,
What about the "new" aluminum matching the rest of the cover? Didn't I read something here about that being a problem. Is it that off?
I thought if I could just get the dent out, the amount of aluminum needed for the crack would be so small, it'd be hardly noticable.
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It's beyond hope, might as well send it to me. lol You should see the ugly welding on the one I bought. I think a weld would be difficult to polish out to match depending on the welder. I'm a welder by trade and an ex welding instructor. I would first try putting it on a piece of wood and try cold hammering with a ballpeen hammer, tapping only in the center. Then back fill it for a seal with jbweld. Heating it will make it more malleable but aluminum will oxidize very easily. If you do weld it, I would suggest tig welding only. It is the only way to control the heat and keep from damaging the aluminum further. Otherwise, as in the case of the cover I bought, which was apparently stick welded or migged, you end up with a big funky glob to grind down.
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Perhaps a safer way would be doing it in a press with proper support around the hole. Otherwise I don't know. But I have fixed a couple with a hammer without adding any more damage.
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Bikenstein,
I saw that cover you got on eBay..... I definitely don't want that welder touching this one! ;D ;D ;D
Just some followup questions for you, I thought cast aluminum like this would be too brittle to be hammered, is that not correct? Also, what did you mean when you said "but aluminum will oxidize very easily"? More so than it already does? I'm not sure how heating would have any affect on future oxidation. ???
Thanks for the tig welding tip.
Mike
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I've managed to remove dents from a Honda 450 cover after my brake pedal ruptured it. It took the hammer quite well without cracking or breaking as some cast iron would. But different castings can react differently. Pressing on it with a vertical press would be safer. Heating aluminum can be tricky because it doesn't turn red when at the melting point it just turns shiny. It wouldn' be necessary to get it near the melting point to make it bend easier but because it transfers heat so rapidly to the surrounding area it would be difficult to isolate one spot with heat. That's why I feel better with cold bending. It was damaged cold and didn't shatter. And if you did cause further damage, weld it at that point. I'm not a metallurgist but enough heat will cause oxidation. Oxy-acetylene cutting is in effect rapid oxidation or rapid rusting of metal and then you blow it out with the oxygen stream. I'm not sure about the future effects of the finish after welding but there will be a heat effected zone around the edge of the weld that may react different than the base metal. And if the welder gets it too hot, even though it's repaired, it can become very brittle. It really doesn't look that bad.
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Not my field here but I believe the aluminum will blend in well. The question is can the welder add the minimum amount of new metal in and then grind out the excess smoothly. Find the best welder you can. This is not bridge work.
I don't think you are going to have a problem, as your damage is minimal. I was told that it is when you start filling in voids that it gets trickier.
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You're right it is not bridge work. Even very experienced welders cannot perform this seemingly simple task. The main problem with welding cast aluminum, I've found, is porosity. Welding aluminum requires much higher heat than steel because of its high conductivity and the more heat you apply the more hydrogen is absorbed into the weld area which causes porosity in the weld and the metal surrounding it. Hydrogen will dissolve easily in molten aluminum but will not blend in when it solidifies. This is the major cause of porosity in aluminum welding. Also oxidation plays a major factor because aluminum oxide has a higher melting temperature than the base metal itself. Therefore the more heat applied the more oxide forms and requires even more heat to melt . That's why you can't cut aluminum with a torch, you can only apply heat until it falls out in a bubbling glob. That's also why T.I.G. welding works best but only on a.c. with a round tip and high frequency. In the positive cycle half the oxide is cleaned from the surface and the negative half you get penetration. So in effect you are cleaning then welding 100's of times per second. I even clean the filler rod of its oxide with steel wool just before welding. Also the filler you use is determined by the base metal alloy type which could include copper, magnesium, zinc, or silicon. Then if you do make a successful weld there is still the heat affected zone at the edge of the weld that is going to be much weaker than before because its crystal structure has changed and probably its polishing characteristics. If a welder has 50 years experience, but little or none welding cast aluminum (especially side covers), I highly doubt that he will do much better than the guy who welded my cover. Mine probably started out with a relatively small dent and a leaking crack but after the guy chased it around and tried to fill the porosity as it formed he ended up giving up with what is left and then still applied jbweld inside to keep it from leaking. If it was as simple as taking it to the welding shop and gettin a little weld on it and just grind sand and polish it out like new, we would have been doin it since back in the day and there would be no question about how to fix one now. I have many years experience in job shop welding and fabrication, pipe welding, tube welding, stainless, aluminum, magnesium, cast iron, brass even plastic. You can check out my old website (cambarfitness.com) and see my line of fitness equipment that I designed and marketed for a few years. I don't claim to know it all, but I would try cold bending first and welding as a last resort. That little dent could end up looking like mine. If you find someone else more knowledgeable or has successfully welded a cover where it can be polished out like new please let me know. When I get my shop set up I'm gonna do some experimentation myself.
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WOW! Very informative Bikenstein, I really appreciate you taking the time to explain this in such detail. I know it's a small boo-boo per se, but being as picky as I am, I'm after "looks" as well as functionality.
I may have to wait till I get back up to Houston to find someone with that kind of knowledge and experience. This small border town I'm in now seems to only excel in wrought iron gates and burglar bars! ;D
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Glad you joined the site and are enjoying it. Thanks for the insight. As I was reading your last post and looking at the cover that was welded for me, it made sense. We will have to wait and see what is under those lumps.
I will let you guys know. Hoping for the best but expecting the worse. Hopefully it turns out better than what I had!
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Bikenstein, Great information, happy you took the time to type it all out. Yes I do think we need some 350 covers made, please HELP RICHARD! ;DJeff Bar
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Ok Bikenstein, good news, the dent is gone. I got the ol' hammer out and started pounding away and what ya know, it worked! ;D
At the right angle & light, you can still see the hairline crack but I'm hoping that once it's polished up, it'll hardly be noticeable.
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Hey Pup,
Good job, what is your plan for the corrosion? I have a pretty badly corroded one myself. Not sure how to attack it, let us know if you come up with any good solutions.
Thanks Mike
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Mike, If you look at the pic of the cover in the beginning of this thread, you'll see all the corrosion that was on the same side as the dent.
In the past, I've used a sanding block and worked it till my hand & fingers gave out. >:( This time I used an electric palm sander and it worked great. Took me about an hour to get the side with the dent to look that good. (that includes rounding up all the supplies and setting up)
I used 220 grit wet/dry with a spray bottle of soapy water to keep everything lubed up. I'll probably start the other half of the cover using 200 grit first. It should make the job go a little quicker. After I get all the corrosion out, I'll work it down using a progressively finer grit and finish with a 1500 or1600. Might even go to 2000 or 2500 depending on how it looks.
I was a little concerned using an electric sander since this is a "wet operation", but there was very little splash or flinging of water with the palm sander. To err on the side of safety however, I did wear a pair of rubber gloves... just in case! :o
The smaller tight areas and curved sections will need to be done by hand.
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Moonpup,
I see what you mean, hadn't looked back at the beginning of the post. Looks like you have made good progress. That should work for mine also, thanks. I will probably use air tools, don't need any surprises.
Later Mike
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Air tools would definitely be the safer way to go for sure, however since I haven't had the time yet to get a 220v line hooked up in the garage for my compressor, I had to go with what was available. For anybody else going the electric route, take precautions and be safe!
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Ok Bikenstein, good news, the dent is gone. I got the ol' hammer out and started pounding away and what ya know, it worked!
Nice job. Better'n tryin to weld it. When I get hold of a Hi-freek welder I'm gonna try repairin one. Post a picture after polishin it.
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Moonpup,
I have put some casings in the bead blast cabinet, and then i wet and dry and then polish.
And i have got dents out by heating the casing then putting in my press and very carefully
Pressing the dent out bit by bit, i put with different Pisces of steel between the casing to
Form the original shape back it takes time but it works.
Thanks.
Steve.
PS at sometime i will post a picture to show what i am talking about.
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I just thought I'd throw in my two cents' worth on the subject of bending aluminium. You're right that you need to be careful heating alluminium, as it melts at a low temperature and when it does so it goes very quickly indeed.
The method I use is to cover the offending item with soap lather, then heat it gently in a flame until the soap lather dries out and the residue turns black, then quench the item in a bucket of cold water. The ally will now bend quite easily, but the metal will work harden as you bend the component. If the component begins to need more force to bend it before it's back to the correct shape, get the soap lather out again and repeat from stage 1.
I've successfully used this technique many times to straighten cylinder and barrel fins and handlebar levers. I've even straightened a bent choke/starter lever, wich is quite thin and delicate. If you try cold bending, though, the chances are that the item will crack or break. It's amazing but true - A minor spill can easily bend a brake lever into a banana with breaking it, but as soon you apply force to the cold lever to straighten it,.... SSSNAPPPP!!
Graham
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but as soon you apply force to the cold lever to straighten it,.... SSSNAPPPP!!
Graham
You're absolutely right about that, happened to me when I was experimenting with a brake lever that already had the "ball" tip broken off and was bent as well. SSSNAPPPP!! ;D However, cold hammering the cover worked for me.... go figure. ;D
On a side note, has anyone ever tried using this stuff to repair holes/gaps/cracks on their covers? Looks like it'd work to fill things in, but I wonder how close a match it'll be once polished out.
http://www.durafix.com/ (http://www.durafix.com/) (there's lots of videos on youtube that you can check out)
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Moonpup, I wouldn't braze that cover of yours. For any effect you would have to open up the crack. It's doubtful that it would match the polished cover. I'd try it on a scrap part first. A severe bend like levers undergo, requires heat to successfully straighten because they are bent past 90 degrees. If they are only bent a few degrees like the covers, you can still cold bend them without the risk of cracking
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It's doubtful that it would match the polished cover.
That's what I was wondering about and why I was asking if anyone had tried the Durafix stuff. ;D
I'd try it on a scrap part first.
That's the way to go. Now, who's going to be the first to experiment? ???
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I think you should go ahead and try it on your cover since it has that awful lookin crack in it ;D
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Aluminum brazing material has been around since the 60's, at least. I've not had great luck with it, but if you get the heat right, it will fill a gap. It was a little difficult to keep from getting bubbles, etc. for me. No telling what the color match will be, but it has to be better than a big crack or gouge, plus in the location behind the brake pedal, it is not very obvious. Most people have had difficulty with color match even with TIG or MIG, so it may be worth a try.
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Why not just weld it from the backside and grind it down? I wouldn't think the crack is that noticeable from the outside.
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Why not just weld it from the backside and grind it down? I wouldn't think the crack is that noticeable from the outside.
When I started this thread, I was more worried about getting the dent out than anything else. Now that that's been accomplished, the crack is a non-issue as far as I'm concerned. I'll just slap a little JB weld on the back and be done with it. ;D
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I think that might be the best route to go.
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Hey guys, I got so pumped getting the dent out of the other cover, I went and started on another one before I've finished the first! ;D
This cover had a dent similar to the first one as well as a fairly deep gouge left by the brake pedal. In addition, the raised area on the right side suffered a good amount of road rash. Wish I'd taken some "before" pic's but I guess I spaced out on that.
Because of the deep gouge & rash, I tackled this one a little differently than the first one and so far it's worked out great. After I pounded the dent out, I used a file holding it flat to the surface and slowly took layer by layer off till most of the blemishes were gone. That's where it stands now and I'm more than happy with the results. The file saved me a ton of time that I would have spent on sanding in order to get to this point.
The first pic highlights the problem areas and the second one is with the file I used. The third pic shows another hairline crack, but this time it's on the underside of the cover and once sanded & polished should all but disappear.
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Pup,
Cover work looks pretty good. You might want to go into the cover repair business. Seems like you are having as much success as anyone else I have seen. Good luck,
Later Mike
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Thanks Mike. Have you started on your heavily pitted one yet? If so, how's it going?
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Nope,
Haven't had time to work on it yet. Putting things together on my original gold gto and getting ready to reinstall the body on my 56 corvette today. Yahoo, been a long time.
Later Mike
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Hey gang, here's a 3rd. cover I attacked today. Luckily there were no cracks in this one, but it did have 2 small dents with fairly deep scratches and an indented area on the bottom edge. Here are the before & after pic's....
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Good job looks really nice Jeff bar
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Good job looks really nice Jeff bar
Thanks Jeff. I'm still amazed at how easy it is to pound out the dents. Before Bikenstein convinced me to give it a go, I was sure any attempt would end in disaster. :o
After doing 3 of these now, I've found out I would rather tackle dents and scratches over oxidation any day. The problem with oxidation is that it usually covers the entire cover and that means you have to remove quite a bit of material which is a whole lot more work.
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What material is the surface you are pounding against?
...bert
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Bert, I'm using the flat pounding surface (anvil) on the back of my bench vise.
Making sure the outside surface of the cover is laying perfectly flat, I use a large bolt that's approx. 1 3/4" long with about an 18mm head to beat it out. I usually start at the highest point and then fan out until the dent is gone.
For larger dents, I start with a block of hard wood and then switch over to the bolt. So far, this is what's worked for me. ;D
BTW: I also picked a bolt with a head that curves down a little towards the threads on the outside edge , so that there's less chance of the edge cutting into the aluminum. I also sanded the surface of the head to remove any imperfections and to make sure it was flat.
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Amazing results! Should look good as new after polishing.
Steve S.
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Moonpup, I would not have guessed your answer. Expected something more compliant, but the results don't lie.
To echo what Steve S. said, Nice work!
Yet another new trick to try! I love this place...Thanks alot...
...bert
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Moonpup,
Nice job well done!!
Thanks.
Steve.
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Those Covers Look Great Do You Sand Them With A D A Sander Before You Polish GENE
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Those Covers Look Great Do You Sand Them With A D A Sander Before You Polish GENE
I just use a combination of the palm sander and hand sanding. These aren't that big, so once you get past the big scrapes & scratches, the finish sanding goes pretty quick.
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As a follow-up, I recently bought this polishing kit from Harbor Freight for when I get time to actually start some polishing. ;D
Got it mainly for all the different little buffers that will allow better access to the more difficult sections of whatever I'm working on.
http://www.harborfreight.com/14-piece-aluminum-polishing-kit-98707.html (http://www.harborfreight.com/14-piece-aluminum-polishing-kit-98707.html)
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Looks to me like you need an apprentice. ;D
...bert
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Looks to me like you need an apprentice. ;D
...bert
Bert, my current situation just doesn't allow me much time for projects. You see, I'm currently my Mothers' sole care giver and her present condition means I have to be available to assist her at a moments notice. I work on things as time allows.
Make that 2 apprentices! ;D
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I'm a welder too , been doing it on pipelines, nuclear stations, oil rigs and refineries for decades, 1975 to be exact.
I repaired a right side cover last year , tig welded it using an AC plant, it has to be done like that to have half a chance of a good job, now the problems I had were I couldn't find a grade of aluminium wire that matched the casing.
It's really expensive to get spectroanalysis done on it to determine exactly what the grade is so I did a small bit with my first choice of aluminium wire and it cracked, again and again, I dug the back out and used my second selection and it cracked and had porosity all through it, which looks like tiny bubbles on the surface if you don't know what that is, so I dug it all out again and cleaned the metal right back then used a wire that is very difficult to work with which is why it was my third choice, now that did not crack but again it had porosity in abundance but I persevered and got it reasonable looking , but when I had a guy polish the casing up properly the new welded area is so much brighter than the existing casing that it stands out like a sore thumb, it would be ok to use if painting the casings were an option or it could be chromed to look the same all over, but then the other side would need done to match.
I have welded casings before and did a lot of pipe and plate aluminium so I generally know what i'm doing but that casing defied technique and perseverance and my conclusion is it's a very low grade aluminium casting with built in defects and if you can get away with not welding one that would be best, however that's not to say somebody might not get lucky and just have either a decent casting or have a matching filler wire.
I also agree with everything Bikenstein has written , he obviously knows my trade well.
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Don't throw away that carb cover with the hole punched thru it..... get creative! ;D
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What does "throw away" mean??
??? ;D ::) ;)
...bert