New HD HAWT windmill progress.

[margusten]

Hi,

Reporting some progress building my new windmill.

Salvaged magnets:

Big Skoda (car) disc brake hub with welded stator fix:

My coilwinder:

And test stator:

I've heared that better glue magnets to disc using Xyanin and Epoxid glue.

So I did.

Because Epoxid glue is too expensive, I decided to add polyester resign.

After hardening it looks this:

Polyester not good for rotor!

I should add some epoxide around magnets.

[margusten]

Here is zoomed part of last picture:

How can this happen?

Do I need to add something to polyester resign next time?

BR,

Margus

[electrondady1]

it is difficult to see from your photo margusten.

did the resin shrink?

[wdyasq]

You don't need to see anything - you can read about the shrinkage and lack of adhesion in the data sheet.(they are available.)

Ron

[margusten]

Yes,

You can see resin shrinked a lot.

Next time I will try another resin.

Or is it possible to add something to avoid this shrinking effect.

[electrondady1]

margusten,

 as old sourpuss has pointed out,in his uniquely curt and critical way, polyester resin does have a tendency to shrink.

my question was to establish if this was the problem that you found offensive.

if this is the case, perhaps the rotor,after it is fully cured,  could be re-coated ether with more resin or a coat of paint.

[electrondady1]

also, it is possible to thin automotive body filler(glass fibers and fillers) with more polyester resin .

this will allow it to be used to cast.

the nice thing about polyester is its cheap and widely available .

 

[wdyasq]

This is an example of stupid following ignorant. When resins are thinned they shrink more. They still don't adhere properly. The answer is not to use more of a bad product, the answer is to use the proper product.

A lot of the problems encountered in life have been experienced by others and those experiences have been documented. By reading and remembering these things one can avoid  making the same mistake.

The bad things about polyester resin make it not work properly for wind turbine applications.

Ron

[phil b]

Hi Margus,

I had a problem similar to yours. I was able to seperate the magnets from the metal disk and resin with a putty knife. A few of my nickel plated magnets and disk were rusted because the polyester let in water.

Afterwards, I used "liquid fusion" by superglue to glue them back in place. $3 for a tube at the local hardware store. I also coated the magnets in this stuff and painted the entire rotor. The problem seems to be solved. 2 years and waiting...

[electrondady1]

polyester resin always seems kind of greasy after it cures

maybe wipe it off with acetone or lacquer thiner.

don't for get to sand the surface a bit before painting.

and no steel wool!! ha ha