Sheet aluminum --- what-- no film ?????

[fairchild]

Just bought some more .025 and .032 here local. he said he wasnt carrying it with the plastic film on it
because too many people complained about the film...... WHAT ???????????????
Who is it buying this product that thinks the film is a problem ?????
I will NOT buy any more that does not come with film on both sides....... (I hope he can order it with film)

Is what all of you are getting have the film ?????? ( I hope-)
Tim

[Archer39J]

I wouldn't think to ask either way. But I don't see a problem with a sheet that didn't have the vinyl, perhaps even for a discount? Doubt it, it'd probably be considered a service to remove it

[Chris In Milwaukee]

When I ordered my aluminum, I asked to have the film put on by the supplier (it was extra). Didn’t think that I’d have to ask to have it put on *both* sides! So much for common sense! Now I have a lot of one-sided aluminum sheets.

[Bcone1381]

I had to pay extra also for the film from my local supplier.

[rodsmith]

[QUOTE=fairchild;n37076]Just bought some more .025 and .032 here local. he said he wasnt carrying it with the plastic film on it
because too many people complained about the film...... WHAT ???????????????
Who is it buying this product that thinks the film is a problem ?????
I will NOT buy any more that does not come with film on both sides....... (I hope he can order it with film)

Here's why you might not want film. The white film that comes on the quick build wings, at least when I bought mine, if left on too long essentially becomes one with the aluminum. Admittedly I left it on several years, The only way I found to remove it was a heat gun and plastic scraper, followed by a scrub with xylene to remove the remaining residue, 25 hours of quality time with each wing. The outboard panel on one wing had clear film on and that peeled right off. Just a warning, something I wish someone had told me. Having said that, if your local dealer can't get you film covered aluminum best place I have found to order aluminum is Airpartsinc.com in Kansas. They sell by the foot of 4' wide coil. Order at least 6' and they can roll it for shipment, saves huge on shipping and stores conveniently. I think everything I bought had clear film on one side, but check with them on that.

[Bearhawkdoc]

I keep going back to Aircraft Spruce. All the aluminum sheet I have received from them has had the clear plastic on both sides. I have also found them to be less expensive. For example, right now Spruce has a 4 X 8 ft sheet of .025 2024T3 for a cost of $88.94, whereas Airparts.com has the same listed for $114.00.

[fairchild]

Thats cheap---- depending on how much shipping is---- (from spruce)
I am not going to "stockpile" my materials - so peeling it off shouldnt be a problem. I had some with clear that was 1 year old and it didnt
want to tear much- though it might given more time.
Honestly--- I want film on both sides---- it just reduces the chances of getting a scratch that scraps the part. There will probably
be enough scrap to go around anyway just from mistakes as it is. I see at least 1 rib that i will scrap because of deep scratches on
the material I didnt notice. That material was kicking around for a year or a year and a half with film only one side.
.025 is so thin you dont have a lot of room to sand/polish out scratches.
I will be cutting out my blanks first on the band saw--- so with no film I have to try to figure out how to prevent the table from scratching it....

IDEA------- I remember that the big box stores sell plastic film with adhesive backing that you stick down on your carpet when you
are doing interior construction work. Wonder if I am "good" enough to apply that to the sheets without getting bubbles or wrinkles ?
Might be a 2 man operation...... flypaper-esque.......

Tim

[Chris In Milwaukee]

I used that material when ripping my spar caps. Took some work to get the bubbles out, but it was temporary, so didn’t need to expend a lot of energy on it.

[bergy]

I've had some problem storing aluminum without plastic film on it. My stuff had paper between layers. Little critters of some sort (spiders maybe) had wiggled in between the layers and left behind some substance (spider-poop perhaps) that left little tracks on the surface. Not enough to feel with one's fingernail, but visible nonetheless

[fairchild]

Yes-- the surface is very sensitive to every foreign substance it seems----- dont want ANY of that----

[SteveF]

Plastic film or not doesn't really matter in the long run. It only protects against superficial scratches and most scratches and tool marks are caused during fabrication and assembly, not shipping and storage. Sometimes you can cause more damage trying to remove the plastic than it would have had if it never had any film on it to begin with.
If it's a real concern, you could just use masking tape to protect the metal while marking, cutting, filing, sanding, forming, drilling, etc and then remove the tape before installation. You're eventually going to alodine, primer, and paint the sheet metal though, so superficial scratches aren't anything to be too concerned about. Gouges are another story, but thin plastic film isn't going to prevent that anyway.

[SteveF]

...I will be cutting out my blanks first on the band saw--- so with no film I have to try to figure out how to prevent the table from scratching it...

Masking tape layed down edge to edge works well.

[fairchild]

Im afraid of masking tape on for any more than 1 or 2 days. It can get mean. never had any problem with the plastic.
I have to completely disagree on the plastic not making any difference in the long run. Not been my experience.
My personal feelings are that on something as thin as .025---- there is so such thing as a superficial scratch. If I see a scratch--
if I cant get it out quickly (not much depth missing) - it goes into the scrap pile.

And now that someone brought up the alodyning----- say I cut a rib out-- form it to shape with rubber pad and rubber
dead blow hammer.... correct me if I am not understanding this correctly---- but that "working" should not have disrupted
the clad on the surface----- the clad is pure Al and soft---- more malleable than the work hardened core. So i would think
the clad should follow where ever the core goes without breaking or cracking or parting. so -- if that is true--- the only place
left with no clad would be the cut edges. If all that is correct--- that inclines me to consider not alodyning the parts that I didnt
have to polish any scratches out of. ( the "perfect" parts. ) maybe just epoxy prime. Only alodyne ones where I had to work
out a defect. (hoping there wont be many of those)

I could see alodyning every part if I wasnt using clad......

Is this good or bad reasoning ? Feedback ? I have to figure this out because I might be priming soon- well- relatively soon..... :-)

Tim

[Archer39J]

Just my experience, but I was amazed how little protection seemed to have been done on a certified aircraft. Piper is also pretty inconsistent with what they do and don't prime, at least it seems in the 70s they were. These panels haven't been opened in almost 40 years and the bare aluminum, even those exposed to blast air/rain, were fine. I'm not positive if these were alclad, but I imagine they were. It now seems less a concern to me then it once was.

[SteveF]

Im afraid of masking tape on for any more than 1 or 2 days. It can get mean. never had any problem with the plastic.
I have to completely disagree on the plastic not making any difference in the long run. Not been my experience.
My personal feelings are that on something as thin as .025---- there is so such thing as a superficial scratch. If I see a scratch--
if I cant get it out quickly (not much depth missing) - it goes into the scrap pile.

And now that someone brought up the alodyning----- say I cut a rib out-- form it to shape with rubber pad and rubber
dead blow hammer.... correct me if I am not understanding this correctly---- but that "working" should not have disrupted
the clad on the surface----- the clad is pure Al and soft---- more malleable than the work hardened core. So i would think
the clad should follow where ever the core goes without breaking or cracking or parting. so -- if that is true--- the only place
left with no clad would be the cut edges. If all that is correct--- that inclines me to consider not alodyning the parts that I didnt
have to polish any scratches out of. ( the "perfect" parts. ) maybe just epoxy prime. Only alodyne ones where I had to work
out a defect. (hoping there wont be many of those)

I could see alodyning every part if I wasnt using clad......

Is this good or bad reasoning ? Feedback ? I have to figure this out because I might be priming soon- well- relatively soon..... :-)

Tim

I wouldn't be too concerned about the plastic coating, I feel it just offers a false sense of security, but it's not my time, money, or aircraft, so do whatever makes you comfortable.
As far as alodine, I alodine every part before I prime it or assemble it. It's worth the effort to take the extra step in corrosion prevention.
Aluminium cladding is only about 5% of the thickness, so on a 0.025" sheet, that's only 0.00125". You can probably rub through that with your fingers. The metal on the outer side of the radius is being stretched, so I can't imagine that the Al cladding stays intact there, and even if it does, it will be significantly thinner after being stretched around the radius.

[fairchild]

The question about the clad stretching is something i probably need to find out about. (to determine how much alodyneing I need to do)
Maybe I could ask somebody like the fellow who used to build warbirds from all most scratch at the Kissimmee airport. He is just fininshing
an F-82 now. maybe it will be at sun-n-fun.
Tim