Dremel?

[Dave Fritz]

I have a platter with a band of black gesso around it. My plan was to use a bit to dimple indentations in the black so when clean up the wood from underneath would show, like polka dots. The dremel burned the wood instead of cutting it leaving an indentation that was burned. Do you think that's because of the bit or the speed of the dremel? Thanks for your assistance.

 

[John Torchick]

I think it is a combination of both. Experiment with a piece of scrap (nothing is scrap to a wood turner) and try using the lowest speed and light pressure. I have countersink bits that will do that but not concerned as they are not visible when the screw is driven in. Let us know what you find. This is how we all learn from each other.

 

[hockenbery]

My wife says you have to do it fast or you burn it.
Tap tap tap

Like John say practice with the same wood and gesso until you get a rhythm that produces results you like.

 

[Mark Wollschlager]

Some wood burns really fast, cherry for one.
When the burr loads up and it is not cutting fast burning happens quickly.
The gesso might be loading the burr. you can sometimes clean it by tapping another surface like a crepe rubber bar or burning the crud with a small torch.
Is it a high speed steel 2-3mm ball or carbide?

 

[Owen Lowe]

In addition to all the other comments, make sure you are using the “sides” of the burr rather than the end. The end doesn’t have much cutting action and will create a lot of friction to get anything done.

 

[Gerald Lawrence]

I think Mark hit it with bit loading. Something Dixie Biggs teaches is loading a burr and using it to burn in dimples. To do this and not burn use low speed and light touch

 

[Dave Fritz]

Thank you. I did use the side of the bit and it worked much better. Gerald, the light touch really helped. Now I need to learn how to steady my hand so the bit doesn't skate on me.

 

[Gerald Lawrence]

Dave for skating you can use one hand to hold tool and the other to hold your wrist so will only get wrist movement and not your whole arm. Also you can keep the thumb or finger in contact with the piece like a prop. wish I had a picture as words do not do this justice

 

[john lucas]

Good answers. Dull bit, bit loading, too high a speed and cutting with the end (which cuts slower) What I do is a couple of things. ONe is to use a bit smaller than the hole you want. Then rotate it in a circle to enlarge the hole and take really light passes as you get to the size you want. Another option is to use the bigger bit, push it in which almost always leaves some burn, then make a rotary pass lightly to remove the burn. There are cutters out there that do a better job than Dremel cutters. I have one carbide cutter I got from Rio Grande.com that actually cuts and leaves a cleaner hole. Quite expensive but if you do a lot of this would be worth it. If you have a variable speed Dremel slow it down and just take a little longer to do each hole. To keep the skating to a minimum always plunge and move the tool clockwise. This is more of a cutting action and reduces the tendency to skate but it's still there. Gerald gave you good directions on preventing that.

 

[Doug Rasmussen]

IMO, the problem is most likely the bit. The ideal bit would be one designed for aluminum deburring. It'll have fewer teeth than a general purpose bit with deeper space between the teeth. Generally this type bit will have a more aggressive cutting action rather the frictional rubbing you're getting that's making the burn marks.

Go to Amazon, search for "aluminum burr set". You'll find sets specific for aluminum and non-ferrous metals. From the pictures you can see the fewer teeth.