Well I'm pretty much done prepping the HS materials for final assembly, and I've decided ( as of today at least.. )to go ahead and use the AKZO epoxy on the under-structure. I'm aware of the common method of alumiprep and alodine to condition the metal for spraying this stuff on, but I was wondering if anyone here tried anything different, like just scuffing and cleaning ...? Just looking for a simple method that lessens my chemical exposure ( besides no primer at all that is..).
Thanks in advance..
TWJoyner
AKZO Prep Strategy...
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captain_john
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Hi TeeDub!
Do as I do. Scuff in a water and dishwashing liquid and this will bring the oils, residue and oxide into the solution.
I use a grey scotchbrite pad so that the process leaves a good adhesion profile while not scratching away much of the alclad coating.
You may choose to do this only to the non-alclad stuff, only on the faying surfaces or nowhere at all. It is all up to you. This is just what I do and the reasons why I do it.
Merry Christmas!
CJ
Do as I do. Scuff in a water and dishwashing liquid and this will bring the oils, residue and oxide into the solution.
I use a grey scotchbrite pad so that the process leaves a good adhesion profile while not scratching away much of the alclad coating.
You may choose to do this only to the non-alclad stuff, only on the faying surfaces or nowhere at all. It is all up to you. This is just what I do and the reasons why I do it.
Merry Christmas!
CJRV-7
Garmin G3X with VP-X & a TMX-IO-360 with G3i
It's all over but the flying! 800+ hours in only 3 years!
Garmin G3X with VP-X & a TMX-IO-360 with G3i
It's all over but the flying! 800+ hours in only 3 years!
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Cherokee Driver
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While not directly on point...I asked Van's for their opinion of Scuff/clean and spray with Marhyde. They said that while they do not want to be involved in the primer wars...they saw the passing on alumaprep and alodine as being acceptable with marhyde. One could conclude that it should also be an acceptable priming method with Azko. I think it boils down to how much protection you want.
On one end of the spectrum is to do nothing...on the other you go the aluma prep, alodine then hit it with an epoxy primer. I am thinking of scuff, clean and hit it with marhyde where the parts connect. It is easy and light. I'll let the 5th owner down from me worry about the corrosion in 40 years.
Just one opinion.
CD
On one end of the spectrum is to do nothing...on the other you go the aluma prep, alodine then hit it with an epoxy primer. I am thinking of scuff, clean and hit it with marhyde where the parts connect. It is easy and light. I'll let the 5th owner down from me worry about the corrosion in 40 years.
Just one opinion.
CD
RV-8A
Wing Kit (Slow Build...very slow build)
Home of "Skunk Works, Wisconsin Branch"
"Glacial Pace...but lovin every minute of it!"
Wing Kit (Slow Build...very slow build)
Home of "Skunk Works, Wisconsin Branch"
"Glacial Pace...but lovin every minute of it!"
CD, what I did was pick up 2 cheap plastic tubs that were big enough for wing ribs. I poured Alumiprep in one and Alodine in the other. Threw a rib in the alumiprep and scrubbed it with a red scothbrite pad, took it out and rinsed it with water, threw it in the alodine tub, and then took out and rinsed. After it dried I shot it with AKZO. Awesome protection. I use to go with self etching spray can primer but was very unhappy with the results. It rubs off way too easy. You made a very wise choice with the AKZO.
Bill Murrish
RV-8 Fuselage
RV-8 Fuselage
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Cherokee Driver
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Good info Bill,
I have a way to go before I need to prime my innards. I have a couple of cans of Marhyde and was thinking of going that route but I can certainly reconsider.
When I needed to repaint inspection covers on my PA 28 I went through the aluma prep and alodine route with zinc chromate primer and found it worked fine. I was hoping to reduce the hassle given the volume of parts I will be handling. Once Van's gave the nod to pass on the alodine, I thought that was great news. If the process is not durable though, I am sure I will be regretting the choice.
I have zero experience shooting paint from a gun. How simple is AZKO to handle? Thanks for sharing your experience.
CD
I have a way to go before I need to prime my innards. I have a couple of cans of Marhyde and was thinking of going that route but I can certainly reconsider.
When I needed to repaint inspection covers on my PA 28 I went through the aluma prep and alodine route with zinc chromate primer and found it worked fine. I was hoping to reduce the hassle given the volume of parts I will be handling. Once Van's gave the nod to pass on the alodine, I thought that was great news. If the process is not durable though, I am sure I will be regretting the choice.
I have zero experience shooting paint from a gun. How simple is AZKO to handle? Thanks for sharing your experience.
CD
RV-8A
Wing Kit (Slow Build...very slow build)
Home of "Skunk Works, Wisconsin Branch"
"Glacial Pace...but lovin every minute of it!"
Wing Kit (Slow Build...very slow build)
Home of "Skunk Works, Wisconsin Branch"
"Glacial Pace...but lovin every minute of it!"
TW-
Good choice on the AKZO.
I would say that if you're going to do the alumiprep (which I don't think you can skip) then you might as well do the alodine. It is the easiest step (but probably the most toxic!) - just submerge in the alodine then rinse.
The real key to AKZO is to make sure you stir the green part THOROUGHLY - not just shake it. You need to get down in the bottom of the can and dissolve the sediment in there. One of those drill attachments from Lowes works great. Once mixed it is very easy to apply - I use this gun:
http://www.sears.com/sr/javasr/product. ... +Air+Tools
Have had great luck with it. Tried some cheap HVLP ones from Harbor freight but had crappy results.
Good luck and Merry Christmas!!
Thomas
-8 wings
Good choice on the AKZO.
I would say that if you're going to do the alumiprep (which I don't think you can skip) then you might as well do the alodine. It is the easiest step (but probably the most toxic!) - just submerge in the alodine then rinse.
The real key to AKZO is to make sure you stir the green part THOROUGHLY - not just shake it. You need to get down in the bottom of the can and dissolve the sediment in there. One of those drill attachments from Lowes works great. Once mixed it is very easy to apply - I use this gun:
http://www.sears.com/sr/javasr/product. ... +Air+Tools
Have had great luck with it. Tried some cheap HVLP ones from Harbor freight but had crappy results.
Good luck and Merry Christmas!!
Thomas
-8 wings
Thanks for all the info guys. I had the same thought process about the alodine step. Pretty simple, so why not just do it... My concern was the toxicity of the stuff, and not wanting to risk exposing anyone in my family to it. I realize the alumiprep and epoxy Isn't maple syrup either, but I have heard the alodine is very nasty stuff. So I think my actions will involve alumiprep with a light scotchbrite scuff, rinse, dry then shoot with the epoxy.
Thanks again..!
TWJoyner
Thanks again..!
TWJoyner
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aparchment
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Rethinking Akzo prep
I am rethinking my Akzo prep strategy and here is why:
1) It's a pain in the rear to have to rinse parts outside in New England in the winter, and I am not about to drag them inside and spill stuff in my house
2) How good is the whole Alumiprep/Alodine method when the Alodine coating rubs off with even gentle handling when I am rinsing
3) I have knocked against the Akzo covered parts with my squeezer while assembling, and the primer came off more easily than I would like causing me to have to touch it up.
4) Napa's 7220 self etching primer that I tried on one set of skins stuck like crazy. This has been my experience with this product in other applications as well (I have used it in model building for many years).
The jury is still out, but word from the bailiff is that they are leaning toward hanging the Akzo.
1) It's a pain in the rear to have to rinse parts outside in New England in the winter, and I am not about to drag them inside and spill stuff in my house
2) How good is the whole Alumiprep/Alodine method when the Alodine coating rubs off with even gentle handling when I am rinsing
3) I have knocked against the Akzo covered parts with my squeezer while assembling, and the primer came off more easily than I would like causing me to have to touch it up.
4) Napa's 7220 self etching primer that I tried on one set of skins stuck like crazy. This has been my experience with this product in other applications as well (I have used it in model building for many years).
The jury is still out, but word from the bailiff is that they are leaning toward hanging the Akzo.
The alodine coating does not / should not rub off. If you leave the parts in the alodine too long, they get a powdery coating and a dark brown color - this brown stuff will wipe off. Leaving them in for 3-4 minutes or less will produce a nice light golden color that won't wipe off.
My results with AKZO are that I cannot scrape it off without LOTS of effort - i.e a bucking bar or rivet set while riveting. Simply bumping or scraping it doesn't even leave a mark. I have tried several other (including the NAPA) self etch rattle cans and there is simply no comparison in durability. Are you sure you stirred the green stuff really really well before mixing?
T.
My results with AKZO are that I cannot scrape it off without LOTS of effort - i.e a bucking bar or rivet set while riveting. Simply bumping or scraping it doesn't even leave a mark. I have tried several other (including the NAPA) self etch rattle cans and there is simply no comparison in durability. Are you sure you stirred the green stuff really really well before mixing?
T.
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aparchment
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Akzo prep
Yup I stir the Akzo part A with a paint stirrer in my cordless drill. I definitely get a consistent mix.
Perhaps I am leaving the parts in the alodine too long and as a result seeing the excess residue wipe off when handling, but once I blow the parts dry, the residue no longer wipes off. See the pic below to see what I mean.
In fairness, the primer that I have scratched off with the squeezer is on edges. It would take a lot to protect an edge from the steel of a squeezer yoke.
Antony
Perhaps I am leaving the parts in the alodine too long and as a result seeing the excess residue wipe off when handling, but once I blow the parts dry, the residue no longer wipes off. See the pic below to see what I mean.
In fairness, the primer that I have scratched off with the squeezer is on edges. It would take a lot to protect an edge from the steel of a squeezer yoke.
Antony
That's too much time in the alodine - it really just takes a short time (1-2 minutes of immersion) to get the light tan / gold conversion. My first ones turned out like that and I had to wipe a bunch of stuff off.
Keep in mind that the alodine gets "used up" - the chromate is consumed as it is used, and it gets less effective. Also, it is sensitive to UV light and will degrade if not kept in the dark.
I hear ya on the winter prep - I just kept working on parts until we got a warm enough day (lots so far this winter!) and then did a whole batch at once.
T.
Keep in mind that the alodine gets "used up" - the chromate is consumed as it is used, and it gets less effective. Also, it is sensitive to UV light and will degrade if not kept in the dark.
I hear ya on the winter prep - I just kept working on parts until we got a warm enough day (lots so far this winter!) and then did a whole batch at once.
T.