Prop Annealing

[Tom Foley]

I need to anneal a few props that I previously oven heat treated and was wondering if I can torch anneal them or must I oven heat them . I would call Marty Davis but i lost his number . Thanks !

 

[Rick Doane]

Tom..........if they are Octura, anneal at 1450 F for 15 min. and quench in ice water bath. Harden at 625 F for 3 hours and let air cool. Pm me if you need other information.

Rick

 

[Jim Allen]

You need to know what the alloy is before attempting to anneal. Overheating beryllium copper alloys will cause the beryllium to leach out. They cannot be hardened without the presense of beryllium, ususlly above 1.7%.

A torch can be used if the prop is C-20 beryllium copper. Heat in a dark room until a dull red color, then immediately immerse in ice cold water. C-275 alloy requires a different procedure.

 

[John Beardslee]

Hi Tom,

If you plan to use propane just keep the flame back aways and bring it up slow. I used distilled water to quench in because it was free of minerals that would oxidize into hard spots that were hard to clean off after you precipitate them. If you use an acetylene torch then use a rosebud tip if you have one and stay way back and bring it up slow. If you have the oven from Stu, 1100 F for 30 min is what I used to anneal. I'd rack the props on rods across a small bread pan and use aluminum foil to make a tent over the whole pan. Did the same tent for precipitating as well - 600F for 30 min. and air cool.

John

 

[John Beardslee]

You need to know what the alloy is before attempting to anneal. Overheating beryllium copper alloys will cause the beryllium to leach out. They cannot be hardened without the presense of beryllium, ususlly above 1.7%.

A torch can be used if the prop is C-20 beryllium copper. Heat in a dark room until a dull red color, then immediately immerse in ice cold water. C-275 alloy requires a different procedure.

Hello Jim,

Have ever done and 2% Berilium to 1/2 or 3/4 hard?

Thanks, John

 

[John Beardslee]

Tom..........if they are Octura, anneal at 1450 F for 15 min. and quench in ice water bath. Harden at 625 F for 3 hours and let air cool. Pm me if you need other information.

Rick

Hi Rick,

That 1450F is a really high number compared to what I used, what's your source and did it work okay? With the small size of our props I found I didn't have to soak (precipitate) for as long as many books or ht specs called for.

Thanks, John

 

[Rick Doane]

Hello John:

I have used these numbers and found them to work well for the Octura props (20C BeCu). This data is available from Brush Wellman, now Materion Brush, web site. It does seem that 1450 F takes it to the edge of melting. ABC props have different numbers and I have not been able to get any information on other prop alloys that are out there. The attached file is from the Materion web site. I am curious how your numbers compare to the ones I have used in the ability to work the prop after the annealing process.

Rick

AT0015-0311 - Tech Briefs - Heat Treating Copper Beryllium Parts.pdf

 

[John Beardslee]

Hello John:

I have used these numbers and found them to work well for the Octura props (20C BeCu). This data is available from Brush Wellman, now Materion Brush, web site. It does seem that 1450 F takes it to the edge of melting. ABC props have different numbers and I have not been able to get any information on other prop alloys that are out there. The attached file is from the Materion web site. I am curious how your numbers compare to the ones I have used in the ability to work the prop after the annealing process.

Rick

Hi Rick,

I purchased BeCu from Brush Wellman in Detroit years ago to cast some of our own props. I can recall if they gave me the numbers or if I pulled them from some of my ASTME text. I found that the octura wheels could be formed or bent with your hands after annealing so they had to be handle with care and of course reprecipitated before running. There we years when my little electric furnace got quite a work out with props going from Warren to Maryland and from Warren to Indy and also alot of local Detroit work as well. It seems to me that Art McMeans told me that his ABC props were 2%BeCu. I still have some raw here and then next trip downstate I'll take on of the klingons with me and have it tested at the college. I bet at 1450F those thin little blades would move when they hit the quench.

Thanks, John

Thanks, John

 

[Rick Doane]

Interesting John. Let us know how that comes out. I would be interested to know if we could lower the annealing temp. based on the blade thickness and considering the hub to blade interface.

Regards............Rick

 

[John Beardslee]

Interesting John. Let us know how that comes out. I would be interested to know if we could lower the annealing temp. based on the blade thickness and considering the hub to blade interface.

Regards............Rick

Hi Rick,

Yes, the info I had circa 1972 was that the larger the volume of material the longer the soak time - so you could reduce the time and lower the temp - the most critical temp is the precipitation temp 600F but there is a range/tolerance there also that would still give you success. The time needed to precipitate (heat treat) is based on size of the material. I'll let you know what the spectrium analysis shows on the old ABC props. I don't have any of the newer ones or I'd take one of them as well. I'll check with some of the Detroit area guys and see if they have any that are bent.

Thanks, John

 

[Tom Foley]

Thanks everyone for all the info !

 

[Jim Allen]

You need to know what the alloy is before attempting to anneal. Overheating beryllium copper alloys will cause the beryllium to leach out. They cannot be hardened without the presense of beryllium, ususlly above 1.7%.

A torch can be used if the prop is C-20 beryllium copper. Heat in a dark room until a dull red color, then immediately immerse in ice cold water. C-275 alloy requires a different procedure.

Hello Jim,

Have ever done and 2% Berilium to 1/2 or 3/4 hard?

Thanks, John

John,

I have only used 3/4 hard beryllium copper alloy #172 for connecting rod bushings. The C-20 alloy that Ed & I used for casting propellers contained 1.9 to 2.15% Be. Its precipitation hardening tmperature for the ultimate tensile & yield was 650 F*, for 21/2 to 3hours. The time was not critical but the temperatures variation was, +-5 F*.

In discussions with Jim Schaffer, "he explained that the alloy he is casting his props from is a Modified C-275 alloy. The props are annealed at 1300 F* & quenched in 11 second quenching oil. After pitching, the prop is de-stressed at 340 F* for 20 minutes. Re-ramp the temperature to 594-608 F* at the rate of 28.8 F*/min. Hold the prop for 40 min to 1.5 hrs depending on the prop. Air cool at room temperature on a cool copper plate, drawing the heat out of the drive side of the hub. The prop must be chemically clean, even fingerprint oil can cause hot spots. The prop blades must not touch anything during heat up or cool down. The lower the Be content, the higher the temp & time. The alloy has been heat treated to Rc-45 in production applications.

There is more information about the use of a salt or lead heat bath. Call Jim Schaffer for this information.

There are four Technical Briefs printed by the Technical Service Department, Brush Wellman Inc. Interesting reading.

1) heat treating copper beryllium

2) hardness testing copper beryllium

3) brazing copper beryllium

4) cleaning copper beryllium

Jim Allen

 

[John Beardslee]

Hi Jim,

Thanks, any idea what the tensile strength is of the C275 alloy is? I've not worked with it as far as I know. The 2% was about 70,000 psi as cast and 135,000 psi after heat treatiing. I haven't found my heat treat log since the move north so I don't recall what the Rockwell readings were.

Thanks, John

 

[Jim Allen]

Hi Jim,

Thanks, any idea what the tensile strength is of the C275 alloy is? I've not worked with it as far as I know. The 2% was about 70,000 psi as cast and 135,000 psi after heat treatiing. I haven't found my heat treat log since the move north so I don't recall what the Rockwell readings were.

Thanks, John

John,

I can't find the charts for 275-C, but i don't think they would apply because ABC uses a Modified 275-C alloy. Maybe Jim Schaffer has that information. I still have the charts from Kawecki berylco Industries which show 160,000 tensile at 40Rc for C-20.

Jim

 

[Jim Allen]

John,

My notes for 275-C show 125,000 tensile with an aging temperature of 653F* for 3 hours. This is very different from the Modified 275C used for ABC props.

Jim

 

[Jim Allen]

Hello John:

I have used these numbers and found them to work well for the Octura props (20C BeCu). This data is available from Brush Wellman, now Materion Brush, web site. It does seem that 1450 F takes it to the edge of melting. ABC props have different numbers and I have not been able to get any information on other prop alloys that are out there. The attached file is from the Materion web site. I am curious how your numbers compare to the ones I have used in the ability to work the prop after the annealing process.

Rick

delete.

 

[Terry Keeley]

Tom..........if they are Octura, anneal at 1450 F for 15 min. and quench in ice water bath. Harden at 625 F for 3 hours and let air cool. Pm me if you need other information.

Rick

What I've used on Octura props for 20+ years.

Anneal, sharpen, balance, pitch then harden.

 

[Albert Araujo]

Jim,

Is the formula you mention for ABC or the Octura props. On ABC I use 1250F for Aneal and 600F for one hour. On Octura I use 1450F to Aneal and 625F for three hours. What are the best numbers for both these props. I threw a blade on one prop last week so would like any help you can offer.

Albert

 

[dwilfong]

Albert

I use the same formula you have and have throw many blades.

I had Norm do a prop for me. It was a radical V cut from Mark and it is still in one piece after a lot of running.

No sure what there recipe is but it seam to work very good.

David

 

[Norm Doerr]

Jim,

Is the formula you mention for ABC or the Octura props. On ABC I use 1250F for Aneal and 600F for one hour. On Octura I use 1450F to Aneal and 625F for three hours. What are the best numbers for both these props. I threw a blade on one prop last week so would like any help you can offer.

Albert

It may not be how you "cooked" the prop causing the blade to come off, could just be the casting of the prop itself and when the prop was worked it made the flaw stand out. However if you are throwing blades several props that you "cooked" you may have to take a look at other things.