Circular patterns-swirls on metal

[chefwarthog]

What is the best way to make circular patterns on the stainless firewall?

[jiott]

One way is to use a Scotch Brite pad on the end of an appropriate diameter wooden dowel chucked in a drill press. Move the steel sheet in a pattern under the pad and bring the pad down with the desired amount of pressure at each pattern location.

[Av8r3400]

It's called pearling, pearlage or engine turning. I just saw an article on this in Kitplanes (http://www.kitplanes.com/issues/33_2/shop_talk/Home-Shop-Machinist-Pearling_21465-1.html) this month. They were claiming that using a wire brush works better than a scotch bright pad on stainless sheeting.

[chefwarthog]

But is the 1/2'' pressdrill has enough clearence to do all the width of the fire wall?:confused:

[Av8r3400]

That may take a little creativity…

This could be done with a hand drill if you are careful.

Lay out all of your target points with a sharpie pen and all you need to do is touch the firewall (laid out flat) with the spinning brush/scuff pad.

On a firewall, with all the wires, cables and stuff attached, if the swirls aren't totally perfect, you will probably never notice… Maybe. ;)

[SkyPirate]

Take a piece of 1/4" HDPE drill with a hole saw the size swirl you want, if you want criss cross overlap , lay out all the rows, do every other row with reversible drill, then do all other rows with drill in forward 👍, usually overlap 1/3rd of diameter of swirl , Id do a practice piece to figure what patern you want 😎

[SkyPirate]

Buy using a piece of HDPE, make it square a little bigger then desired swirl hole saw hole, this way you can clamp a straight edge and use it as a guide, mark the side you choose as top just in case the hole in the HDPE isnt perfectly in the middle

[chefwarthog]

Ok Comprendo!!! Thanks for the info!!! I will practice that on scrap metal....;)