21 Hydro - HydroShock 21

[Chris Wood]

i beleive jim from abc told me at one time that his props have some COBALT in them

chris

 

[Terry Keeley]

Terry:

The ABC props do look more brass colored. I use the process for 275C as Jim described in his post. So far so good. I repaired/treated two ABC S40 props, small blade area, 55-56 mm dia., very thin, mounted on a 1.01 twin, and no change in pitch was observed. These props are alot thinner than the 1667's we normally run. I was impressed. Also, I believe that one has to observe and control the heat values/times for both alloys in order for either to work.

There was a thread (ABC Props) started by me and is in the General forum and dates back to Oct. 1st (about 10 pages back). Heat treating values for both Octura and ABC can be found there.

Regards........Rick

Got it, thanks:

http://www.intlwaters.com/index.php?showtopic=42337&hl=abc props&st=0

 

[Jorgen Andersson]

Thanks Rick and others for detailed info.

A little while ago I did a test and compared an Octura prop from the 1980´s and one bought recently.

As I suspected the old props is stiffer and stronger, you can feel it if you use a file and especially when you use a pair of pliers and bend the blade.

I also had this comfirmed by someone that has prepared a lot of props.

Is it simple less BC in the new ones?

Anyone having more facts here?

I have just started to do some heat treating tests in order to see if it is possible to get the new prop similar to the old one.

As many others say, I also think that "new" materials will be needed.

I have had several racers telling me that they have problems by bent and thrown blades, especially on the 90/101´s.

Thanks

Jorgen

 

[Rick Doane]

Thanks Rick and others for detailed info.

A little while ago I did a test and compared an Octura prop from the 1980´s and one bought recently.

As I suspected the old props is stiffer and stronger, you can feel it if you use a file and especially when you use a pair of pliers and bend the blade.

I also had this comfirmed by someone that has prepared a lot of props.

Is it simple less BC in the new ones?

Anyone having more facts here?

I have just started to do some heat treating tests in order to see if it is possible to get the new prop similar to the old one.

As many others say, I also think that "new" materials will be needed.

I have had several racers telling me that they have problems by bent and thrown blades, especially on the 90/101´s.

Thanks

Jorgen

Jorgen:

I think that you have asked a very good question. Are the props from the 1980's to date, the same alloy and/or mix? I have been assuming that they have been. However, I look at the props that I personally have, and there is a difference in their appearance over time. :huh: It really does not matter if, the manufacturers would publish the hardening information or if we just called and asked, they would tell us. My partner and I have not thrown a blade yet on the 1.01's (knock on wood) even not hardened. But that is just a matter of time. I believe that props on those motors should be hardened.

I would like to see other material/compositions used for props offered. SS props are great but they cannot be repaired like a BeCu prop can unless I just do not know how. I have repaired some very ugly/unusable BeCu props to near original which is only possible through heat treating and the material that is used.

I apologize for keeping this off topic, but if everyone wants it to be moved to another Forum, we can proceed from there. Please keep us informed on your research of various heat treating techniques.

Regards.........Rick

 

[Andy Brown]

Thanks Rick and others for detailed info.

A little while ago I did a test and compared an Octura prop from the 1980´s and one bought recently.

As I suspected the old props is stiffer and stronger, you can feel it if you use a file and especially when you use a pair of pliers and bend the blade.

I also had this comfirmed by someone that has prepared a lot of props.

Is it simple less BC in the new ones?

Anyone having more facts here?

I have just started to do some heat treating tests in order to see if it is possible to get the new prop similar to the old one.

As many others say, I also think that "new" materials will be needed.

I have had several racers telling me that they have problems by bent and thrown blades, especially on the 90/101´s.

Thanks

Jorgen

Jorgen:

I think that you have asked a very good question. Are the props from the 1980's to date, the same alloy and/or mix? I have been assuming that they have been. However, I look at the props that I personally have, and there is a difference in their appearance over time. :huh: It really does not matter if, the manufacturers would publish the hardening information or if we just called and asked, they would tell us. My partner and I have not thrown a blade yet on the 1.01's (knock on wood) even not hardened. But that is just a matter of time. I believe that props on those motors should be hardened.

I would like to see other material/compositions used for props offered. SS props are great but they cannot be repaired like a BeCu prop can unless I just do not know how. I have repaired some very ugly/unusable BeCu props to near original which is only possible through heat treating and the material that is used.

I apologize for keeping this off topic, but if everyone wants it to be moved to another Forum, we can proceed from there. Please keep us informed on your research of various heat treating techniques.

Regards.........Rick

Rick,

Octura has changed twice that I know of. The 60's and 70's props were the strongest. You probably remember those old Octura props with the black spots on them. There are still a few floating around. I saw some for sale on here a few weeks ago. The 80's and 90's props were pretty good, but in 2000-2001 they changed again. It drove us crazy, because we were sharpening and balancing several hundred props a year and suddenly props began bending. At first we thought we were just making them too thin. 1662's and 1667's were the biggest problems. Octura wanted to blame it on new more powerful engines, but we had customers like Joe Warren running the 1662's on his Picco 67 powered Roadrunner and he went from having great success with those prop to instantly bending every one we sent him after a certain date. Octura finally thickened the 1662 and the 1667, but of course that eats up horsepower.

 

[Jorgen Andersson]

Yes, it seems that many of us have the same conclusion/experince.

If they started of with 2.75% BeCu, I wonder how much it could be today?

My first basic heat treating tests with new and old props of the above, gave in hand that the new one is still "soft" compared to the old one,

Tomorrow I will meet a guy that runs a heat treating company, we will see what he can come up with.

I think that SS or similar will be the future material for hard racing.

Thanks

Jorgen

 

[Rick Doane]

Thanks Rick and others for detailed info.

A little while ago I did a test and compared an Octura prop from the 1980´s and one bought recently.

As I suspected the old props is stiffer and stronger, you can feel it if you use a file and especially when you use a pair of pliers and bend the blade.

I also had this comfirmed by someone that has prepared a lot of props.

Is it simple less BC in the new ones?

Anyone having more facts here?

I have just started to do some heat treating tests in order to see if it is possible to get the new prop similar to the old one.

As many others say, I also think that "new" materials will be needed.

I have had several racers telling me that they have problems by bent and thrown blades, especially on the 90/101´s.

Thanks

Jorgen

Jorgen:

I think that you have asked a very good question. Are the props from the 1980's to date, the same alloy and/or mix? I have been assuming that they have been. However, I look at the props that I personally have, and there is a difference in their appearance over time. :huh: It really does not matter if, the manufacturers would publish the hardening information or if we just called and asked, they would tell us. My partner and I have not thrown a blade yet on the 1.01's (knock on wood) even not hardened. But that is just a matter of time. I believe that props on those motors should be hardened.

I would like to see other material/compositions used for props offered. SS props are great but they cannot be repaired like a BeCu prop can unless I just do not know how. I have repaired some very ugly/unusable BeCu props to near original which is only possible through heat treating and the material that is used.

I apologize for keeping this off topic, but if everyone wants it to be moved to another Forum, we can proceed from there. Please keep us informed on your research of various heat treating techniques.

Regards.........Rick

Rick,

Octura has changed twice that I know of. The 60's and 70's props were the strongest. You probably remember those old Octura props with the black spots on them. There are still a few floating around. I saw some for sale on here a few weeks ago. The 80's and 90's props were pretty good, but in 2000-2001 they changed again. It drove us crazy, because we were sharpening and balancing several hundred props a year and suddenly props began bending. At first we thought we were just making them too thin. 1662's and 1667's were the biggest problems. Octura wanted to blame it on new more powerful engines, but we had customers like Joe Warren running the 1662's on his Picco 67 powered Roadrunner and he went from having great success with those prop to instantly bending every one we sent him after a certain date. Octura finally thickened the 1662 and the 1667, but of course that eats up horsepower.

Andy....Stan tells me all the time that my stuff belongs in the Smithsonian!! (ha) I assume that the Be content may change a little but there would be the addition of other elements to ensure stronger castings for thin cross sections. If the props are bending due to more powerful engines, then the manufacturer(s) need to address that issue and have. If they continue to break due to being too thin, then proper hardening of the alloy is necessary. The key is to know the alloy. I'm sure the exact content of the alloy would not be published but the hardening information can be. As you know, after hardening, any changes needed/wanted makes one spend more time on the prop. I am seeing "as cast" 1667's and 1662's bend (depitch) over time. This is occuring at the TE from the root to the tip.

 

[Rick Doane]

Yes, it seems that many of us have the same conclusion/experince.

If they started of with 2.75% BeCu, I wonder how much it could be today?

My first basic heat treating tests with new and old props of the above, gave in hand that the new one is still "soft" compared to the old one,

Tomorrow I will meet a guy that runs a heat treating company, we will see what he can come up with.

I think that SS or similar will be the future material for hard racing.

Thanks

Jorgen

Jorgen:

If you have any scrap metal businesses in you area, they should/may have a hand held X-Ray Defraction instrument. They can shoot your props and tell you exactly whats in them.

Rick

 

[Jorgen Andersson]

Rick

Good idea.

Do you think that they will be accurate enough in this case?

Jorgen

 

[tobbec]

Hello...

So it sounds like next time ill get new prop it should ss instead of berulium...

I actually never tested ss prop yet, havent have breaking prop problem yet. But as speed go up it might be the case...

Time to learn about ss next year then..

 

[Rick Doane]

Rick

Good idea.

Do you think that they will be accurate enough in this case?

Jorgen

Jorgen:

I cannot say that it will be that accurate but what other choice do you have besides asking the makers? The scrap metal people live and die by their numbers. I have used this instrument for elemental analyses in soil and it is pretty damn accurate. If you have the composition of the metal, you can take this information to your heat treating contact and ask what the values should be. It is worth a try.

Rick

 

[Jorgen Andersson]

Rick

I will go to a place on Friday that have this device and test a few props, new and old ones.

I keep you posted on the results.

The heat treating guy says that this info could be helpful for him.

Thanks

Jorgen

 

[Rick Doane]

Jorgen:

Did you have the chance to test you props yet?

Rick

 

[Jorgen Andersson]

Hi Rick

Yes, I did the test last Friday.

I do not have the print outs in front of me, but there are more BeCu in the old prop.

The old prop is from 1984 or older, and the new is from last year.

The new one was around 1% and the old one was around 3%.

My heat treat contact will now use this info and do some tests.

Thanks

Jorgen

 

[Rick Doane]

Hi Rick

Yes, I did the test last Friday.

I do not have the print outs in front of me, but there are more BeCu in the old prop.

The old prop is from 1984 or older, and the new is from last year.

The new one was around 1% and the old one was around 3%.

My heat treat contact will now use this info and do some tests.

Thanks

Jorgen

Excellent. It's good to see that one can discover the difference using this technique. Thank you for sharing your results.

Rick

 

[Rudi Arnesen]

I used to work with BeCu some time ago. The service industry (offshore drilling for oil) uses the material due to the characteristic of the material combined with radioactive sources while performing target drilling from the platform.

I used to work in a company where we manufactured drilling equipment for this purpose.

It is well known that BeCu tends to change in material structure over time, it becomes more brittle.

At some point of time the material becomes too crispy, and the equipment is considered junk.

Based on this I think it could affect the props over time and tending to have us believe that it is only the change in amount of BeCu that is influence on breakage of the props.

What I do know is that the BeCu is very toxic and are now banned form use in the oilfield in the North Sea.

The material is similar to Asbestos, once it’s in your lung, its stay there.

 

[tnrcboatracer]

Maybe the BeCu props need to be annealed, checked for pitch and cup, and then re heat treated every year or two. The chage over time would be aging or age hardening. guess it can go too far and get overly brittle. Perhaps it is something to do with the grain structure or crystal growth.

 

[Jorgen Andersson]

Jon

Yes, maybe this could be a good idea.

I am waiting for the results from the heat treating guy after his tests on old and new BeCu props.

Hopefully we can have more SS props in the future so we can leave the BeCu props behind us, for several reasons.

Jorgen

 

[Jorgen Andersson]

Hello

Here we have a couple of pictures of a Japanese 21 Hydro kit that is very much prebuilt.

Price is about $535 or so.

This boat is designed for 6 lap heatracing, not their short track soloracing.

I do not have much details, but if someone have interest of the rigger, please let me know and I will give you the contact info.

http://www.intlwaters.com/index.php?app=gallery&module=images&section=viewimage&img=6862

Thanks

Jorgen