The Mirka, and Festool, are quite expensive.
How expensive are the aluminum panels?
How about just buying new panels?
Keep the old panels and just put some more scratches on them... give them the patina of age?
Unless, of course, you're trying to justify buying more tools ( no need to justify that IMHO ).
How expensive are the aluminum panels?
How about just buying new panels?
Keep the old panels and just put some more scratches on them... give them the patina of age?
Unless, of course, you're trying to justify buying more tools ( no need to justify that IMHO ).
I road raced a Lotus 7 for years, every winter I would spend a few days on the body while the machine shop was busy with my race engines. The Lotus used alloy panels riveted to the tube frame, deep and surface scratches in those panels always needed attention. 3m was and still is my favorite compounds for alloy panels. If I could run my finger nail across the scratch and it would catch, I started with wet sanding using 1500 grit paper using a circular pattern. Next, 3m Perfect IT machine compound with a random orbital with a foam pad. Use very light pressure and let the compound do all the work. If you heat the alloy panels they will distort and will require replacement. After I was satisfied the scratches no longer caught my finger nail, I used 3M Finesse It polish compounds using a 7" DA (Dual Action) machine with a VERY light touch.
The mistakes I saw beginners make with alloy panels was A) using a compound that is to aggressive and B) using to much force with the machine, you just let it float over the panel, the compound does all the hard work.
Don't sand blast or even bead blast alloy panels! Walnut shells or soda blasting is the most aggressive media to use on alloy and should only be used with experience. I suggest you go buy an alloy panel to practice on.
The mistakes I saw beginners make with alloy panels was A) using a compound that is to aggressive and B) using to much force with the machine, you just let it float over the panel, the compound does all the hard work.
Don't sand blast or even bead blast alloy panels! Walnut shells or soda blasting is the most aggressive media to use on alloy and should only be used with experience. I suggest you go buy an alloy panel to practice on.
Late to the party but exactly how deep are these ‘scratches’? Is sanding them out going give you a distorted reflection when seen from certain angles? If you want a polished finished and the scratches are more like small gouges, and you just happen to have a TIG welder in your shop, you can fill before bringing it back down.
Otherwise, a new panel?
Otherwise, a new panel?
The panels weren't cheap, and if I replace them then it's just money down the drain.
If I buy a new sander to repair them then at least I have an asset at the end.
Not only does it feel wasteful to discard the old panels but it feels like an admission of defeat, that I couldn't fix them.
So, not quite an excuse to buy a new tool, but there is an element of that.
But yes, the Mirka is expensive, probably too expensive to justify.
However there are Mirka clones that are reasonably priced and apparently perform pretty well.
Think I'll order today.
As @elwood625 puts it, sufficient to catch a nail.
The panel will have some bends so a distorted reflection shouldn't be noticeable, especially if black anodised.
The bend is part of the reason I am concerned, don't want a crack initiator when the bend is done
I do have TIG but the panel is only 3mm thick, I am worried I would distort it.
I do plan to do this to repair some thicker aluminium parts in a different project, a turntable restoration.
Best wishes
David
hello Dave:
I have repaired scratches in Al. panels by using epoxy resin to fill the really deep scratches and sanding the surface then using an acid etch primer and paint. You could then bake or heat to ensure the finish is hard. Or you could use an epoy paint.
You can also "float" solder into the scratches if you can get it to bond to aluminium.
JB weld for aluminium works for me
Just a few ideas to consider.
Sometimes it is just best to try something rather than over analyzing it
I have repaired scratches in Al. panels by using epoxy resin to fill the really deep scratches and sanding the surface then using an acid etch primer and paint. You could then bake or heat to ensure the finish is hard. Or you could use an epoy paint.
You can also "float" solder into the scratches if you can get it to bond to aluminium.
JB weld for aluminium works for me
Just a few ideas to consider.
Sometimes it is just best to try something rather than over analyzing it