Who can re-chrome a 182 Front Strut?

NordicDave

NordicDave

En-Route
Joined
Oct 31, 2015
Messages
2,737
Location
Monterey County
Display Name
NordicDave
Home Airfield
KWVI
See attached... I bought a 182 which needed the front strut re-chromed. The front strut finally started giving out at the seals and the time has come for a rebuild.

182P%20Old%20Strut_zpsgvpuaurs.jpg


Anyone know of a good resource to have a Cessna 182 front strut re-chrome plated?

Thanks,

-NordicDave
 
What about hydrogen embrittlement? I though chroming was a no-no?
 
It is almost always a standard procedure to "Bake at XXX degF immediately after plating to relieve hydrogen embrittlement". The plater should know about this. I can't remember XXX tho.
 
I hope every one knows the chrome on an aircraft strut is not your regular bumper chrome.
Boeing has theirs done by ASCO processing in Seattle.
I've had two struts done by them, they strip the old chrome off, clean the iron core and re chrome, then send it out to have it re- ground to size. It ain't cheap.
You might better find a good one in a salvage yard.

 
Stewartb said:
What about hydrogen embrittlement? I though chroming was a no-no?
Click to expand...
400 degree bake, bye bye embrittlement
Many aircraft structural parts are CAD plated, same method, relieves the embrittlement.
 
nrpetersen said:
It is almost always a standard procedure to "Bake at XXX degF immediately after plating to relieve hydrogen embrittlement". The plater should know about this. I can't remember XXX tho.
Click to expand...
375 to 400 for 24 hours.
 
Thanks guys for the pointers. A BIG help. I'm surprised more owners are not faced with re-chroming strut tubes. It does not appear a common issue. I looked at used, but they seem pretty raggy, at least the one's I've seen.
 
Please let us know what direction you end up going... and how much it costs.
 
FYI.. I'm calling for quotes and turn around times. Hawker Pacific does not work on Cessna parts. Aerospace coatings charges $600 for tube less then 2 1/2" diameter, with a 3 week lead time and a yellow tag. I have not yet called Chromecraft, though they look completely capable; not sure if they can pul the fork off the tube and re-press then together.
 
NordicDave said:
not sure if they can pul the fork off the tube and re-press then together.
Click to expand...
It's not pressed on, heat the fork to about 400 degrees, then rapidly cool the tube and it will fall apart.
 
Tom-D said:
It's not pressed on, heat the fork to about 400 degrees, then rapidly cool the tube and it will fall apart.
Click to expand...

That's the definition of pressed on. You've described the process to relieve enough friction between the components for fitment.

It's pressure holding the fork and strut tube together. Yes you have to heat one and cool the other so thermal expansion & contraction allows enough clearance for the 2 parts to press together. AS long as both parts are within their size tolerances enough clamping for is available to hold the parts together.

-NordicDave
 
NordicDave said:
That's the definition of pressed on. You've described the process to relieve enough friction between the components for fitment.

It's pressure holding the fork and strut tube together. Yes you have to heat one and cool the other so thermal expansion & contraction allows enough clearance for the 2 parts to press together. AS long as both parts are within their size tolerances enough clamping for is available to hold the parts together.

-NordicDave
Click to expand...
go to --https://www.redskyventures.org/doc/cessna-maintenance-manuals/Cessna_182_1974-76_PartsManual.pdf

figure 36 items 4 & 7 remove those and do the trick I mentioned it will come right off.
no press is needed to install or remove..

To be a press fit, wouldn't one need a press? they aren't that tight.
 
Let's get back to the objective here: you want to re-chrome the strut to extend its life and have a well-sealed nose gear assembly. Here is the process, my comments and your options:

1. From the picture originally posted it is not completely clear what the existing condition of the strut tube is. It's hard to evaluate the wear or determine what is grease residue and what is actual wear or damage to the surface of the strut.
2. As mentioned above, "hard chrome" is not to be confused with "decorative chrome" - completely different process and completely different end result. Hard chrome is applied using an "electro-plating" process.
3. It is not always necessary nor appropriate to disassembly the tube from the fork. The chrome can easily be applied selectively and the need to remove the strut tube from the fork depends on the post-plating grinding operation (see #5 below). As mentioned in the above post some Cessna gear can be completely disassembled.
4. Option: you can choose to "flash" the hard chrome with the intention of performing no secondary grinding operation. This is the least expensive approach. The bigger companies will not do this due to the potential liability of a process that may not conform to the manufacturer's specification.
5. Option: you can choose to perform a more complete process whereby the chrome is built up to an oversized condition, then the strut is fixtured in a large machine and then the new chrome surface is ground down to a very tight tolerance. The machines used to perform the grinding operation have sophisticated fixtures that can hold most any strut assembly without the need to remove the fork. In some cases they will even weld a temporary plate to facilitate mounting the unit in the grinding machine. This is the operation for which you were quoted about $600 and includes an 8130 certification.
6. ANY reputable plating house recognizes that hydrogen embrittlement must mitigated through a post-plating baking operation. Using either option #4 or #5 the plating house should provide a "certification of compliance" to give you assurance that this has been done.
7. Don't forget that you may need to replace bushings in addition to the seals in the upper section of your strut. Properly rebuilding a strut assembly is not a trivial task.

Forgive my lengthy reply however I like to be concise and detailed in the information that I offer... Rob
 
Last edited:
Tom-D said:
go to --https://www.redskyventures.org/doc/cessna-maintenance-manuals/Cessna_182_1974-76_PartsManual.pdf

figure 36 items 4 & 7 remove those and do the trick I mentioned it will come right off.
no press is needed to install or remove..

To be a press fit, wouldn't one need a press? they aren't that tight.
Click to expand...
Often the term "interference fit" is used. Sometimes no press is required. Heating the outer and cooling the inner part allow them to slide together and be locked in place when temperatures equalize.
 
GlennAB1 said:
Often the term "interference fit" is used. Sometimes no press is required. Heating the outer and cooling the inner part allow them to slide together and be locked in place when temperatures equalize.
Click to expand...
I wouldn't interfere with it either, junk yards are full of them.
 
Thank you Rob58!

I called all the suppliers recommended in the above threads and Aerospace coatings seemed to really understand Cessna front struts. Asko for example, wanted me to supply all the detailed engineering requirements like materials to be used and final dimensions. Aerospace Coatings just needed the correct Cessna part number.

The strut pictured top of thread; The black stuff near the top of the tube is just fluid seeping past the seals. The black specks on the lower part are chipped chrome.
 
You are welcome NordicDave! I think you are making the right decision to go with Aerospace Coatings. Let me know if you have any other questions and give us a report after you get the strut back.
 
GlennAB1 said:
Comprehension ain't your bag, is it...
Click to expand...
Comprehending that what you do or say here has little to do with what the OP will do. If down time has any meaning I'd have one on the way.
 
If the steel barrel is corrosion-pitted where the chrome is off, rechroming isn't going to fix it.
 
Dan Thomas said:
If the steel barrel is corrosion-pitted where the chrome is off, rechroming isn't going to fix it.
Click to expand...
The way it is completed it does. first step is to grind off the old chrome, then it is a process of putting it back, and regrinding to proper size and polishing.
 
NordicDave said:
Looks like this one was involved in a wreck. The upper and lower flanges have mounting holes torn off. Betting a hard landing/prop strike at least.

It's very difficult to find a good used one not worn out.
Click to expand...
it will get you the piece you need.
 
Tom-D said:
The way it is completed it does. first step is to grind off the old chrome, then it is a process of putting it back, and regrinding to proper size and polishing.
Click to expand...
There's no guarantee. On the landing gear I'm familiar with, all the corrosion must be removed and a minimum tube thickness must remain in order to be able to be rechromed.
 
GlennAB1 said:
There's no guarantee. On the landing gear I'm familiar with, all the corrosion must be removed and a minimum tube thickness must remain in order to be able to be rechromed.
Click to expand...
It really is dependent upon the authorized shop practices approved by the Administrator.
What I described above is pretty much how re-chroming is done, shop to shop may vary some but for the most part it's get the old off, put new on, bring it to size.

there are several methods of getting the old chrome off, one of which is a electro-chemical process, which transfers the old chrome to a rod I forget which it is the Positive or the negative pole in the tank.
I've done the tour a couple times at ASCO pretty interesting
 
Last edited:
No, corrosion removal and remaining tube wall thickness really depends upon manufacturer engineering documents, which was mentioned about 15 posts back.
 
Last edited:
Corrosion pitting weakens the strut. Grinding the strut smaller messes up its clearance in the bushing, and too much clearance causes the seals to leak. Chrome plating is awesomely thin stuff and isn't going to replace the removal of .010" of tube diameter.
 
Dan Thomas said:
Corrosion pitting weakens the strut. Grinding the strut smaller messes up its clearance in the bushing, and too much clearance causes the seals to leak. Chrome plating is awesomely thin stuff and isn't going to replace the removal of .010" of tube diameter.
Click to expand...

Dan, You are correct. The strut piston must be returned to original manufacturer's specs if it is to work properly. The other "gotcha" is that the internal bearings must be replaced with new to bring the nose strut into compliance.
 
I once found a pit like that on a Beechjet 400A main landing gear oleo during unrelated maintenance, the tip of pencil lead fit in it. It spent a month on jacks waiting for a new leg assembly.
 
You must log in or register to reply here.
Back
Top