Grinding Welds Flat - How do you do yours??

[Fortunate Son]

Just wondering what people use when grinding down welds after butt welding panels etc. I have heard some say that they use flap discs on grinders, I have found it really difficult not to end up with very thin sheet metal as a result. I have settled for now on my Dremel but it costs me a bloody fortune in grinding wheels (they are 2 quid each!)

Any tips please (I reckon Im missing something obvious )

Cheers in advance, Andy

 

[uber cool]

Use the grinding disc to shift the bulk, then finish off with a flap disc. Using a 100mm grinder.

100mm flap wheels cost about 98p and last a long time.

 

[Air Cooled Rookie]

I've always found a flap wheels on an angle grinder to work fine. I'm not sure that you are missing anything obvious, as there's not much to miss!

Just take care not to put too much heat into the panel - You'll distort it. Ask me how I know :roll:

 

[Frankie]

flap discs are the best way I think just take your time and concentrate on the weld not the metal round it dremel must take forever no? Frankie.

 

[NickJ]

Yep I'm in the flap disc camp as well

 

[james_stan]

My cr@ppy welding often results in nasty 'sticky up' welds but I am using pub gas.

I get the impression (also from mig-welding.co.uk) that argosheild lays flatter welds.

Cheers

James

 

[Justin & Muttley]

Flap wheels all the way - if you're ending up with thin metal then you're being too heavy handed!!

Do it in small sections and don't press too hard or the heat will build up very quickly.

 

[Joval]

I had the same problem with flap wheels, the heat distorting and causing the metal around the weld to rise up.

That's my theory anyway - after a few f**ked up welds.

 

[ProfessorWheeto]

My cr@ppy welding often results in nasty 'sticky up' welds but I am using pub gas.

I get the impression (also from mig-welding.co.uk) that argosheild lays flatter welds.

Cheers

James

Argon does make it easier to get better penetration but you can weld perfectly fine with CO2.

You may want to adjust the set up of your welder. Weld a test piece, something like an offcut of a repair panel and check the underside to see if your getting decent penetration. You may need to up the power and back off the wire speed.

 

[ProfessorWheeto]

I had the same problem with flap wheels, the heat distorting and causing the metal around the weld to rise up.

That's my theory anyway - after a few f**ked up welds.

Flap discs are perfectly fine, sounds like you need to be a bit more patient when grinding.

 

[Clem]

Ive used a air fed belt sander lately .... its fab!

 

[Tofufi]

I tend to end up using flap discs...

Spot the difference

Before...

After...

This is my bugs radio hole aperture...

from:

All the above are with no filler on the joins at all, just the bare metal with a single layer of primer.

and on a rear 1/4 panel (not fully welded yet)

The trick is to get the panels butt welded perfectly in line, meaning you have the same thickness to grind through on both pieces of metal. Also, go slowly with the flap wheel - if the metal begins to discolour and darken, then it is getting too hot and too much pressure is being applied. You may find these useful to get the butt-welds in line - I've never used them myself though.

http://www.frost.co.uk/item_detail.asp?productID=8351" onclick="window.open(this.href);return false;

Apologies for the pics being Bug related, not bus related... but the bodywork repairs I've done to my bug are neater than any I've done to my van :lol:

 

[ProfessorWheeto]

Ive used a air fed belt sander lately .... its fab!

We've got a couple at work (thick one and thin one) Really handy at times!

If you've got a compressor you might also be interested in the little air grinders you can get?

The small cut off grinders and what I call a "wizzer" (not sure if its got a proper name! but its got like a 1 inch wide flap disc) are great.

 

[Fortunate Son]

Cheers for all the replies! Professor W - would like to see a pic of your "wizzer" sounds like a magic tool

 

[Araon]

Professor W - would like to see a pic of your "wizzer" sounds like a magic tool

Ahem wrong forum there fella.... http://www.earlygay.com" onclick="window.open(this.href);return false;

remember "slowly slowly catchy monkey"

 

[ProfessorWheeto]

:lol: :lol: :lol: :lol:

Ok I think its called something like a mini air angle grinder and it takes 2" Roloc Discs

Looks a bit like this...

 

[Fortunate Son]

Nice one mate, looks like Im gonna have to take the plunge and invest in a compressor.

 

[ProfessorWheeto]

It'll be worth getting a air file/belt file as well then.
The air saws are worth their weight at times as well.

 

[Clem]

Yes, Aldi were meant to be selling those small grinders but were out of stock, but they look great. An air-saw? Again, a great bit of kit .... once youve had air tools there is no going back! Just so much easier to work with when there is no hulking great motor to be involved.

 

[ProfessorWheeto]

We just got another wizzer at work...

So I now know its proper name and refer to it by its german name :lol: