| Author |
Message |
    
searcher
Senior Member
Username: searcher
Post Number: 103
Registered: 10-2004
| | Posted on Thursday, May 18, 2006 - 10:15 pm: | 
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Quite often the brass (sometimes bronze) parts on these old engines are found bent to varying degrees. I have a couple of Schebler D's and a Krice carburetor that have bent throttle levers. More importantly, I have a two piece brass Detroit injector with a slightly bent clamp that holds the float chamber cover tight and with a noticeably bent brass threaded tube that conducts crankcase pressure to the float chamber. I know what will happen if I try to straighten any of these items by bending them back into position. How does one straighten these things without breaking them? By annealing? Is bronze treated differently than brass? |
jb_castagnos
Senior Member
Username: jb_castagnos
Post Number: 124
Registered: 07-2002
| | Posted on Thursday, May 18, 2006 - 11:14 pm: |
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I believe non ferous metals are treated the same, heat to a dull red and cool. Some recomend quenching in water, air cooling gives the same results. Straighten the part a little, if it work hardens anneal again as often as necessary. This is best performed in an area with dim light, when brass turns dull red it's not far from melting. |
searcher
Senior Member
Username: searcher
Post Number: 104
Registered: 10-2004
| | Posted on Friday, May 19, 2006 - 12:17 am: |
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JB, Thanks for responding. Now, for the follow up question. In order to keep the Detroit float chamber from leaking, the arm that puts tension on the float chamber cover requires tightening a nut. Overtightening the nut is what bent the arm in the first place. Annealing is going to leave the arm rather pliable and even more subject to bending. Is there any way to harden the brass a bit once the arm is back in the proper position? |
jb_castagnos
Senior Member
Username: jb_castagnos
Post Number: 125
Registered: 07-2002
| | Posted on Friday, May 19, 2006 - 07:13 am: |
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This would require heat treatment, controlled temperatures over a long period of time. Brass and copper also work harden, a roll of copper tubing that's soft and pliable when new will be hard to work if it's left bouncing around in a truck tool box. Seams like you best bet here is to use a sealing compound, silicone won't work for gas, maybe one of the Permatex lines. I know you don't want to glue it together. |
searcher
Senior Member
Username: searcher
Post Number: 105
Registered: 10-2004
| | Posted on Saturday, May 20, 2006 - 10:39 pm: |
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Thanks JB. It took me so long to find a Detroit injector of any kind that I am reluctant to do anything that might damage it. However, one of these days the appearance of that bend will overcome my reluctance and I will try the annealing route. |
Duane s
Visitor
| | Posted on Thursday, June 15, 2006 - 12:32 pm: |
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worked with a black smith when I was a teenager, he had told me, when you want to anneal something heat it to the tempature required then put in powered lime to keep the air from getting to it, this will let it cool very slowly, and should be the softes it will get, could take a couple of days to cool. Then do the work on it, then heat it to the tempature
required and quench quickly keeping it in tell cool. that well harden it again to it highest strenght. We were working with steel, but might work for you. if you were doing a
chiesel you would quench scrape off slag and look for color bands to move to the end of the chiesel and quench when again. |
ernie
Senior Member
Username: ernie
Post Number: 405
Registered: 01-2002
| | Posted on Thursday, June 15, 2006 - 05:27 pm: |
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Duane,
To anneal or soften metals.
You are correct with your procedure for ferris metal. Heat it and let it cool sloooowly.
Non Ferris metals are just the opposite. I did an extensive search using Google to back up what I have been doing for years, and this is what I found over and over.
Bronze/Brass/Copper Heat to a medium red; quench when the
Copper redness disappears. However be carefull at the medium red color. It's not far from liquid at that point. I do this all the time and it works well. |
Duane s
Visitor
| | Posted on Thursday, June 15, 2006 - 11:08 pm: |
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thanks,
I have not worked with those metals learned something new!
Duane |
capt_ed
Member
Username: capt_ed
Post Number: 5
Registered: 12-2007
| | Posted on Wednesday, July 09, 2008 - 10:41 am: |
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I freed up a frozen lower part of an old air cooled 3/4 hp outboard about 35 years ago, was aluminum gearcase , heated it let cool in air , no good, then heated it again with acetylene carefully and quenched it in a 5 gal pail of cold water and it rotated freely , seems if quenching restores something, dont know if its more brittle or softer , maybe it only affected the bearings, i wouldnt hesitate a quick quench on copper, it does get softer, never tried brass |
kerrigan
Member
Username: kerrigan
Post Number: 4
Registered: 06-2008
| | Posted on Wednesday, July 09, 2008 - 05:25 pm: |
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Open this link: http://www.metalimprovement.com/shot_peening.php
Shot peening can harden non ferris metals. Don't attempt the process with a 12 gauge or B.B. gun. |
