Need ideas to remove dents from spun aluminum please
#1
04-11-13, 07:59 PM
Need ideas to remove dents from spun aluminum please
Hi all,
I have a large rooftop exhaust fan, the common commercial style with a spun aluminum dome over the motor. The dome has been severely dented by falling ice from a commercial TV tower, and looks pretty bad, but the fan still works fine.
Since the company no longer manufactures this model of fan, I'd like to take a shot at trying to remove these dents, but I'm not sure of what I should try. Any ideas or advice would be greatly welcomed!
Thanks,
Andy
I have a large rooftop exhaust fan, the common commercial style with a spun aluminum dome over the motor. The dome has been severely dented by falling ice from a commercial TV tower, and looks pretty bad, but the fan still works fine.
Since the company no longer manufactures this model of fan, I'd like to take a shot at trying to remove these dents, but I'm not sure of what I should try. Any ideas or advice would be greatly welcomed!
Thanks,
Andy
#2
04-12-13, 04:38 AM
It depends on the severity of damage. You may be able to push the dents out with the palm of your hand. If the metal is creased you will need a hammer and dolly (auto body tools) and the skill to use them. The metal may have been stretched and you'll probably never get it looking flawless though. Last resort, bring it to an auto body shop. Since there is no painting involved, the charge may be reasonable.
#3
04-12-13, 10:32 AM
Thanks Toolmon!
Some of the dents are pretty deep, and it's thick (12 gauge aluminum) according to an old catalog. I will try the hammer & dolly technique, which I did kind-of learn in auto shop WAAAY back in high school.
Andy
Some of the dents are pretty deep, and it's thick (12 gauge aluminum) according to an old catalog. I will try the hammer & dolly technique, which I did kind-of learn in auto shop WAAAY back in high school.
Andy
#4
04-12-13, 11:50 AM
Super Moderator
A sand bag is also a good tool. It allows some movement, but not too much and supports the surrounding area.
You see them being used all the time on the bike and car customizing shows.
You see them being used all the time on the bike and car customizing shows.
#6
04-12-13, 02:31 PM
The sandbag idea makes a lot of sense, as this is a big bowl shaped object. I'd place the bag underneath & hammer from the inside?
Dry ice??? Guess I'll have to research that one- never heard of that technique, but it sounds interesting.
Andy
Dry ice??? Guess I'll have to research that one- never heard of that technique, but it sounds interesting.
Andy
#7
04-12-13, 03:19 PM
I believe the dry ice is applied around the wound and the expansion/contraction differences causes the wound to heal itself without hitting on it. Handle the dry ice carefully, as it is 170 degrees below zero F, and hurts when it freezes. Check around on the street corners. They will have a tent set up and will remove dents without the need for painting afterwards. There may even be a YouTube or more about it.
#8
04-12-13, 03:19 PM
Super Moderator
Yep...bag underneath and mallet used on the inside normally. I've also seen where a smaller bag is mounted on some sort of post made out of pipe and the dished object is inverted over it, then the exterior is hammered.
You need to use a big enough mallet or hammer that you don't just move small amounts or the metal will stretch and get work hardened. Either that or carefully work in from the edges of the dent.
Theres a reason the body mechanics that can hand work aluminum get paid big bucks.
You need to use a big enough mallet or hammer that you don't just move small amounts or the metal will stretch and get work hardened. Either that or carefully work in from the edges of the dent.
Theres a reason the body mechanics that can hand work aluminum get paid big bucks.
#9
05-11-13, 03:14 PM
Update!
I finally got around to this repair job this morning, and it turned out pretty well! I pounded the dent out with a rubber mallet on a sandbag on the floor. It is by NO means perfect, but looks pretty good overall. The smaller dents disappeared with one fairly hard blow, and the large one took a bit more doing, working from the outside of the dent toward the middle.
Thanks to all for your advice! Next job is to remove the 4 coats of paint, down to the bare aluminum.
Andy
Thanks to all for your advice! Next job is to remove the 4 coats of paint, down to the bare aluminum.
Andy
