pudestcon

Hmm , Looks like the same part on the T500.

I'll check it out next time.

Have you had a chance to check it out, and did you find anything?

Pud

Hi Dick,I think you will find any reference Pud might have made to pinning would have referred to his Tail wheel thruster, as you rightly point out, pinning the mains with forward stick in a tricycle undercarriage aircraft is asking for trouble and haven't we seen plenty of C172 wheel barrows out there .... oh dear....

David

Dick, Yes I understand what you are saying as I have a bit of time on a Gazelle, but my comments in this thread relate specifically to a T500 Thruster in a 'wheel on' landing.

Cheers,

Pud

Curiosity excited the pussy.i_dunno :ah_oh:

Pud

Thrusters, Drifters, grass and dirt...........all been discussed. Now there's one golden rule for GRAVEL strips, Don't let any aircraft drift sideways or land at an angle to the strip 'cause you'll take years of life off your tyres. I drifted in a Jab fitted with reasonably worn tyres and ripped the tread off. The tyre blew just after shut down.

Pud

No worries Mike,

Sorry it wasn't what you were looking for.

Is it still for sale do you know?

Pud

Hi Pud.I'm speculating the parts are made from 2024 alloy. (Based on your observations and mine of the powdery white corrosion)

It's usually known as "machining grade".

 

It has abysmal corrosion performance, even sitting on the metal rack in the shed it gets covered in a white frost.

 

Given the operating conditions, a 606x alloy would have been a much better choice for this part (or even marine grade 5052 alloy).

 

I think the original designers were led astray by the appeal of the higher UTS (60,000psi) of the 2024 vs ~40,000 & 30,000 psi for the other grades.

 

---------------

 

Ok My machinery handbook says 2024 is prone to intergranular corrosion, so I google it up

 

Intergranular corrosion - Wikipedia, the free encyclopedia

 

and in Paragraph 5 it says aluminium alloys with copper (=2024) are subject to exfoliation corrosion, resulting in leafing or lifting effect , which pretty much describes the photos in the AD.

 

A few more similar links:

 

Intergranular corrosion

 

Different Types of Corrosion: Intergranular Corrosion - Causes and Prevention

 

Different Types of Corrosion: Exfoliation or Layer Corrosion - Causes and Prevention

 

http://canteach.candu.org/library/20053207.pdf

 

Metal Improvement | Exfoliation Corrosion

 

(the above suggests cadmium plated fasteners may be implicated)

 

Exfoliation Corrosion - JAMWiki

 

and a tutorial on aluminium grades:

 

Argentum Solutions Inc. - Sterling Guidance on Corrosion and Materials Degradation

 

--------------------------------

 

Interestingly enough Austenitic stainless steel is subject intergranular corrosion after welding. This goes part of the way to explaining the failures on the other half of the wing attachment, where the TIG welded parts have the end of the weld (= stress raiser) near the high stress bend.

 

Perhaps the whole thruster wing attachment method might be a good example of "how not to design something" for an engineering class.

 

Cheers, BobT

Are you a metallurgist?

The more I learn, the more I realise I don't know - but I've known that for a long time about all manner of things.

It's going to take me some time to read through the links you have provided. Thanks very much.

I'm satisfied that the treatment I have done to my struts will provide the integrity I'm looking for and daily and/or preflight inspections will keep me on top of it.

There is no doubt that maintenance on these rag and tube type aircraft is very high, but then, that is what we accept in our choice of flying machine.

Cheers,

Pud

G'day Bob,

Yeh it does seem a bit cheeky by the manufacturer I'd agree.

I wonder who manufactures them in Australia now - the alum. plug I mean.

The plugs on my struts are not anodised and did not show any signs of the type of corrosion referred to in the order.

Here's a couple of photos of my 'work in progress' on the struts.

Pud

I'm looking to purchase a CA 25 Skyfox - anybody out there got one they are interetsed in selling? Condition is not too important as I'm happy to repair - but I don't particularly want a crashed one.

There is one available at Bindoon in WA

Pud.

A guy stuck his head into a barbershop and asked, 'How long before I can get a haircut?

The barber looked around the shop full of customers and said, 'About 2 hours.'

The guy left.

A few days later, the same guy stuck his head in the door and asked ,

How long before I can get a haircut?'

The barber looked around at the shop and said, 'About 3 hours.'

The guy left.A week later, the same guy stuck his head in the shop and asked, 'How

long before I can get a haircut?

The barber looked around the shop and said, 'About an hour and a half

The guy left.

The barber turned to his friend and said, 'Hey, Bob, do me a favor.

Follow that guy and see where he goes. He keeps asking how long he

has to wait for a haircut, but then he doesn't ever come back.'

A little while later, Bob returned to the shop, laughing hysterically.

The barber asked, 'So, where does that guy go when he leaves?

Bob looked up, wiped the tears from his eyes and said, 'Your house!'

Pud

Those of you with UK design Thrusters (the Vision series, I believe) may be interested in this service bulleting from the Thruster factory. It affects all UK Thruster types using the aerofoil section struts. [added] Only those with aluminium alloy strut ends, steel ones are OK.http://www.thruster.co.uk/documents/TAS_SB013.pdf

 

Joan

 

www.saxonMicro.co.uk

The photos show what looks to be a very similar part to that used in almost all Thrusters including the T500. I have just refurbished the struts on my T500 and this included removal of all 4 aluminimum plugs from the struts, inspection for corrosion (found a little surface "white rust"), treatment to remove the corrosion and apply boiled linseed oil to internal surfaces as per Tony Hayes literature, then etch prime and paint all exposed surfaces.

Check it out Thruster drivers as this is a major structural component helping keep you in the air.

Cheers,

Pud

I ended up with an older woman at a club last night.

She looked OK for a 61 year-old.

In fact, she wasn't too bad at all, and I found myself thinking that she probably had a really hot daughter.

We drank a bit, and had a bit of a snuggle, and then she asked if I'd ever had a Sportsman's Double.

'What's that?' I asked. 'It's a mother and daughter threesome,' she said. I said, 'No' - excitedly.

We drank a bit more, then she said that 'tonight is your lucky night'. We went back to her place.

She put on the hall light and shouted upstairs..........'Mum, you still awake?'

Pud

As a baby-boomer, unless you're a deadbeat dropkick, a "refugee" or an unwed mother with four kiddies from four different donors, it's likely there'll be little left in the public coffers by the time you qualify for age-related government support (and then Centrelink will look for every reason to penalize you if you have managed to put something aside). So put a foot in both camps (like Nev says don't touch something you can't shake loose from if you hit a bad patch but, like Maj - if you can arrange to have your cake & eat it too on someone else's capital at a manageable cost, go for it. As an aside, how many of us remember the good /bad old days when the banks would loan you money only if you could prove you didn't need it? Cheers

"Have your cake and eat it too" translates to "Harvesting your equity to live off and buy stuff with". Banks will lend you for this purpose depending on how much equity you have and how much you want to use. Rule of thumb for you - on a yearly basis, use half the capital growth of your assets. That way the tactic is ongoing and self supporting. The catch - you need enough appreciating assets to start with.

The wonders of OPM - not that mind altering substance Opium, but a life changing strategy called "Other Peoples (the banks) Money.

Cheers,

Pud

Maaate,

That was magnificent!

Thanks for sharing

Pud

Looks good from my POV Tomo.

Well done

Pud

My sincerest condolences BigPete. May your dearly loved wife Anne rest in peace.

Pud

Well your prop really stands out eh JG3? I'm just gonna leave mine black with yellow tips probably to match the pod on the Thruster.

Spraying would be the way to go Tomo for an even, uniform and light cover

I'd be surprised if a light coat of ArmorAll wouldn't bring that up as new Pud.

That's what I'm gonna try then. I'll let you know how I go.

Thanks

Pud

After looking at the prop today I reckon a coat of clear lacquer will do the trick.

Here's a photo of the prop - what do you think?

Pud

Thanks everybody for your thoughts and observations, and views on the subject.

I took delivery of the 2 new ss brackets today and they are a perfect replica (without the bend:laugh:) of the existing bracket so should fit seamlessly onto the spar. They will be fitted in the next week or so.

If anyone needs a stainless steel fabrication company in WA then go here Stainless Steel Sheet Metal Fabrication Perth Western Australia

Cheers,

Pud

Pud;Since the prop is composite, why not just some polish. The coating is too thin to cause unbalance, but makes an old prop look much better. It does have to be reapplied periodically.

I didn't think about polishing - what would you recommend using?

Pud

Pud,I would be very wary of painting a prop unless you have an appropriate way of re-balancing it when you are done.

 

Cheers

 

Mick

Yeh I am aware that the prop will need rebalancing, and that is something I need to study up on before I attempt any painting. I'll need to hit the books and ask lots of questions to see if it is a DIY project or all too hard (and safer:helmet:), so leave it alone.

Cheers,

Pud

My Thruster will be fitted with a s/h prop from a Thruster that I did all my conversion training in, so I know the prop is serviceable. The prop does look a little shabby so I want to paint it to look like new. It's a 3 blade composite prop (sorry don't know the brand) so how do I go about painting it? Sand it back, primer, top coats, what sort of paint? All questions I need answers to, and I'm sure you guys will be able to give me much advice about it:big_grin:

Cheers,

Pud

PudWith all due respect to learned formites here-in, we're talking about a Thruster here - not an F-18. Despite the characteristics of stainless, straightening that minimal degree of bend is not likely to create a potentially catastrophic failure situation. Doctrine (and common sense) requires close inspection of these brackets for cracking at each pre-flight anyway but if it remains a concern, include a die penetrant test with your 50 hourlies. Any breakdown in the integrity of these brackets will visible in the lead up long before the point of separation is reached. cheers

I'm interested in the die penetrant test; can you do that yourself or is it something you would have an expert do? What about having the bracket xrayed - would this work on stainless steel?

Pud

G'day Pud,In my opinion a good choice. That's what I use in the Thruster and I do think a lot about this topic. I got 20 litres from the local Castrol dealer for I think $131 making $6.55/l. Far better deal than Super...p!

My bit, Don

Cheers,

Pud

Down to two types

Well after doing a bit of research tonight I reckon I'll try Castrol Active 2T (on the strength of Maj's recommendation along with ozzietriker), and/or the new Aeroshell Sport Plus 2 although info is a little sketchy still.

The Castrol Active 2T is available for $39.65 4 litres at Supercheap as well;)

Pud