Alum Panel Treatment

[Railroad]

I am stumbling along, working in different areas every day, it seems. I am fitting and drilling the trunk alum, after installing the drop box and battery box. I lack installing the cubby kit.
My question, does anyone leave the bottom and outside of the alum panel bare? I am considering wiping down with Sharkskin, leaving bare, or painting. I am not going the powder coat or Sharkhyde route. I plan to use the peel and stick stuff on the inside of the cockpit and trunk. Any advise on the options I have listed will be appreciated. If those listed are big No No's feel free to advise me so.
Thanks

[phileas_fogg]

Panel treatment appears to be one of those builder-preference things. At build school, both instructors said that they had left their aluminum panels bare. The cars were 7 and 10 years old, and showed no ill effects.

I painted the surfaces that didn't get covered in peel-n-stick. I roughed up the surfaces to be painted with 80 grit sandpaper, then wiped it down with acetone. Then, I scrubbed the to be painted surfaces with PreKote (http://www.aircraftspruce.com/catalog/cspages/prekotesurface.php?clickkey=7243) according to the application instructions (under the documents tab of the product description), rinsed the firewall thoroughly with water from the hose, and let it air dry. Then I sprayed with two coats of high(er) temperature paint (http://www.amazon.com/dp/B00N04BVOC/ref=sr_ph?ie=UTF8&qid=1444070868&sr=1&keywords=hammered). All this prep is probably overkill, but I don't want the paint peeling off.

Following the same preparation steps, I covered the road-facing surfaces with Duplicolor truck bed liner instead of paint.


John

[2bking]

I used rattle can undercoating on the under side of all the panels but wasn't durable until after several months of drying. I scratch off many places while working on the car and was constantly reapplying. Now, more than a year later, it seems hard and tough. For the areas you are going to carpet and or apply peel and stick, might as well leave the panels bare so the adhesive will stick well. For my panels that were going to show when all was done, I quickly sanded them with 120 grit on a RA sander and buffed them with a green scotch bright pad and applied a clear coat of lacquer.

[NAZ]

Too bad you're not considering Sharkhide -- that stuff works great and lasts longer than the clear coats I've tried.

[edwardb]

At build school, both instructors said that they had left their aluminum panels bare. The cars were 7 and 10 years old, and showed no ill effects.

Like nearly everything with these builds, just depends on what you want. "No ill effects" I'm assuming means still structurally sound. Unless you live near the ocean where corrosion can be a concern, can't disagree. However, the bare aluminum will turn a grey color. Some like the patina. Others may not. Plus it will stain and be harder to keep clean. If that's important to you.

I personally like powder coat, but then I both show and drive my cars. It stays looking brand new and is easy to keep clean. It's not particularly cheap, but in the grand scheme of the total build budget, a small percentage. Worth it for me. I know not for everyone though. DIY methods (paint, Sharkhide, undercoat, polish, etc.) are cheaper, but there are a lot of panels and you can sink a lot of time into it. My time has value to. (At least I like to think so... :))

As far as finishing "what shows" again depends on your definition. From the engine compartment? From the wheel wells? From the underside? I want everything that shows, regardless of where, to be finished. There are literally only a couple pieces that don't have at least one side showing somewhere. Again though, a personal choice.

[Gumball]

Mine are bare and I just wipe the visible ones down with a rag that has a little WD-40 on it occasionally - they all still look new.

[Mark Reynolds]

Clear anodize after all drilling and fitting.

[Railroad]

Thanks all, for the advise. Leaning toward Sharkskin for the bare alum unseen and covered by the body. Considering paint on the visible alum, and peel and stick under the interior and trunk areas. Will do the bedliner stuff on wheel wells and heavy splash areas. Subject to change with the wind.

[mmklaxer]

For the painted panels, a self-etching primer (Zinc Chromate or similar) will improve adherence.

[2FAST4U]

Sanded with 320 wet/dry. Leaving as sanded


http://i23.photobucket.com/albums/b373/GT40_Bill/IMG_2577_zpstaiyzsqx.jpg (http://s23.photobucket.com/user/GT40_Bill/media/IMG_2577_zpstaiyzsqx.jpg.html)

http://i23.photobucket.com/albums/b373/GT40_Bill/image_zpsa81o6dxm.jpeg (http://s23.photobucket.com/user/GT40_Bill/media/image_zpsa81o6dxm.jpeg.html)

http://i23.photobucket.com/albums/b373/GT40_Bill/image_zpsdw1ro7og.jpeg (http://s23.photobucket.com/user/GT40_Bill/media/image_zpsdw1ro7og.jpeg.html)

http://i23.photobucket.com/albums/b373/GT40_Bill/image_zps50kfnio4.jpeg (http://s23.photobucket.com/user/GT40_Bill/media/image_zps50kfnio4.jpeg.html)

[Railroad]

2fast4u, very nice. Did you hand sand with a block or use a powered sander?

[Dave Howard]

If the budget will stretch a few hundred$$$....go the powder coat route

[Jazzman]

If the budget will stretch a few hundred$$$....go the powder coat route

Entirely agree, but would add to do all powder coating in one batch. Multiple small batches increases cost. (Ask me how I know!!) Also keep in mind what will be seen and what will not be seen. If you aren't showing the car, the floor panels will be covered in carpet, and the underside won't be seen unless you are less than 4" tall or you flip the car over . . . in which case you have bigger issues!! The back wall will be covered in carpet, but the outboard wings will be seen inside the wheel wells and the top will be seen in the trunk. The Trunk aluminum might or might not be covered in carpet on the inside, and only the side walls will be seen inside the rear wheel wells. Don't bother coating only one side of any panels. It doesn't save you any money. The inboard and front of the foot boxes and the firewall will be seen inside the engine bay. The outboard foot box panels cannot be seen unless you follow in my footsteps and do the Flip Top Mod! The F Panels can be seen in the engine bay. If you do it all in one batch, it isn't too expensive, and really sets off your build as one of quality!

Good luck with your decision.

[Railroad]

Thanks for the tips on paint and coating. Love the hammered powder coat. I have the anniv ed, so the foot boxes are already coated white. I am still fitting the alum panels. Also, still mentally wrestling with which route to go. I wouldn't mind seeing some alum to define the car as a built car and not a production item.