35 replies to this topic

[skoughi]

Just bought a draper rotary tool (same as a dremel but not as expensive) and was giving the accessory's a try. The little grinding stones were certainly not up to a mig weld though!! I've been looking at diamond grinding bits on ebay and was wondering if anyone else has any experience with these things and what you use?

[Sam Walters]

Just bought a draper rotary tool (same as a dremel but not as expensive) and was giving the accessory's a try. The little grinding stones were certainly not up to a mig weld though!! I've been looking at diamond grinding bits on ebay and was wondering if anyone else has any experience with these things and what you use?

They are mostly useless for work on a car.

What i use:

Grinding disk in a 4 & 1/2 inch grinder. Flap wheels to suit grinder.

What i plan to buy:
Power file with some decent belts
Decent rotary burr set

Edited by Sam Walters, 26 March 2011 - 10:10 AM.

[Chris_R]

The grinding stones in those accesory kits are great for plastic and aluminium but whenever I've tried them on steel they just turn to dust!

[Bungle]

have you tried a power file ?

[skoughi]

The head of one came flying off the shaft when i used it for about two minutes!!!! I was looking at a 30pc set of diamond bits but it's only about a fiver so is it a case of you get what you pay for!! I will be using the angle grinder on 99% of the bird sh*t that i pass as welds but its those bits where the grinder can't fit that i'm needing something.

[skoughi]

have you tried a power file ?

Don't have one and i've blown this months tool budget on the rotary tool, but i can see where you're coming from.

[mini93]

you will be there forever!
use an angle grinder with a flap wheel, will take the surfaces off the welds easy

[skoughi]

you will be there forever!
use an angle grinder with a flap wheel, will take the surfaces off the welds easy

Aye a welder at work suggested this, i usually use a grinding disc then finish with 36 grit disc. Think i will maybe get a flap disc and try one, or i could get better at welding instead!!

[mini93]

there could be that but hobby welders can be difficult to weld with, if you can weld good with a hobby welder, by time you switch to a man sized welder you will be doing well.


something like this... Link

bit on the expensive size

[Sam Walters]

there could be that but hobby welders can be difficult to weld with, if you can weld good with a hobby welder, by time you switch to a man sized welder you will be doing well.


something like this... Link

bit on the expensive size

But they last well aslong as your using them for final finishing and not grinding down welds.

Edited by Sam Walters, 26 March 2011 - 10:35 AM.

[sonikk4]

there could be that but hobby welders can be difficult to weld with, if you can weld good with a hobby welder, by time you switch to a man sized welder you will be doing well.


something like this... Link

bit on the expensive size

But they last well aslong as your using them for final finishing and not grinding down welds.

They will last even when grinding down welds, however you need the coarse grit 60 or 80 and do not press hard. For final finishing 120/180 will be fine but because they cover a larger area you can still go mad and thin the metal too much. Just need to ask my son about that, he meant well but i needed to replace the floor panel i had recently fitted because he spent tooo long polishing up the welds.

Personally i use a standard grinding disc until the welds are nearly gone then use the flapper disc to polish up and any final fettling i use a 3" inch Roloc disc on my high speed air grinder. You still need to be careful as if the area you are grinding has distorted slightly you may do more damage.

Due to me being a fussy bugger i grind all of my welds flush apart from any areas that are hidden but again those that i grind flush i make sure that i have got 100% penetration.

If the car is being used as an every day driver etc and not a show mobile then as long as the welds look good then you can leave them alone. Shifty does his like this so really its each to their own on how they want their welds to look.

Use the Dremmel in those really hard to get to areas but do not press hard. If not use these in a high speed grinder

Burrs

[skoughi]

there could be that but hobby welders can be difficult to weld with, if you can weld good with a hobby welder, by time you switch to a man sized welder you will be doing well.


something like this... Link

bit on the expensive size

But they last well aslong as your using them for final finishing and not grinding down welds.

They will last even when grinding down welds, however you need the coarse grit 60 or 80 and do not press hard. For final finishing 120/180 will be fine but because they cover a larger area you can still go mad and thin the metal too much. Just need to ask my son about that, he meant well but i needed to replace the floor panel i had recently fitted because he spent tooo long polishing up the welds.

Personally i use a standard grinding disc until the welds are nearly gone then use the flapper disc to polish up and any final fettling i use a 3" inch Roloc disc on my high speed air grinder. You still need to be careful as if the area you are grinding has distorted slightly you may do more damage.

Due to me being a fussy bugger i grind all of my welds flush apart from any areas that are hidden but again those that i grind flush i make sure that i have got 100% penetration.

If the car is being used as an every day driver etc and not a show mobile then as long as the welds look good then you can leave them alone. Shifty does his like this so really its each to their own on how they want their welds to look.

Use the Dremmel in those really hard to get to areas but do not press hard. If not use these in a high speed grinder

Burrs

Thats the laddies i probably am looking for! Any links foe where to get them and likely prices?

[quinnyj]

A good quality bur set aint cheap ....

[DAVEY_C]

them bits are great but only realy in a high rpm rotary tool, hobby rotary's won't be up to it..... air is the only way to go in the future imo but as of yet you can only work with what you got so its worth a shot mate. oh and get some flap discs, their also quite esential, take it slow and keep on the welds and you'll be fine. i get mine on ebay and i get 4or5 for that screwfix price and last well for finishing.

another one i find usefull to have are flap wheels... can get into certain spots a disc can't and come in various sizes.

[Shifty]

I wouldn't be using a dremmel type tool in this way, its not what it was intended for. All you'll end up doing is blowing it up and having nothing to show for it.

A 4.5" angle grinder and some flap wheels are the weapon of choice, not hugely dear, £40 for a grinder and £1-£2 per flap wheel.

A dremmel is ok to cut out had to reach metal but thats about it.

As already said, don't do mad when grinding welds back, the more you grind the weaker the joint. If you make it look really pretty by grinding it flush you stand a good chance of removing most of the strength in the joint.

Leave a little flush then either finish with filler or seamsealer.