Welding Tips and Tricks

Which flap discs?

What grit for removing mill scale? What grit for finishing?

Cheap ones in ten packs, or expensive singles?

What other essential wheels are liked?

I have a bunch, but having trouble removing mill scale with flap disc on 5" Bosch angle grinder. Maybe wheel is old/plugged? It also takes forever to re-shape tool steel combination wrench with 5" metal grinding disc.

You might try the 3M Bristle Discs on mill scale.

Larry

I buy 40 grit and 60 grit mostly but I have a few that are down around 120 or 150 that I keep around just in case.

Where the heck can you get cheap flap disks?
I saw my old boss buy ten boxes (10 per box) of them at one time because he got them for $5 a box. Not sure how he came across that deal but I'd sure like to find a deal like that myself. I just paid $8 for one 40 grit disk at home depot a couple of days ago.

RamboBaby wrote:Where the heck can you get cheap flap disks?
I saw my old boss buy ten boxes (10 per box) of them at one time because he got them for $5 a box. Not sure how he came across that deal but I'd sure like to find a deal like that myself. I just paid $8 for one 40 grit disk at home depot a couple of days ago.

The last ones I bought I got from Harbor Freight. They had a good price on an assortment package. As I recall it had three different grits of flap disks and several cutoff disks all for about the price of one at Home Depot. Harbor Freight has a 25% off coupon sale running starting today also. I got the notification in an e-mail but you can get one if you just go to the Harbor Freight home page. I don't buy much at Harbor Freight but these seemed more than adequate for the task at hand.

Thanks. I saw them online a few days ago but they look like they're no where near as beefy as the one I just bought. I looked to see what they had because I was so pissed about what I had just paid at home depot. Made in chinese should not cost so much.

RamboBaby wrote:Where the heck can you get cheap flap disks?
I saw my old boss buy ten boxes (10 per box) of them at one time because he got them for $5 a box. Not sure how he came across that deal but I'd sure like to find a deal like that myself. I just paid $8 for one 40 grit disk at home depot a couple of days ago.

I ordered a ten pack of Walter flap discs from Amazon for $10 but after a two week delay, they didn't honor the price and removed all traces of the order from my shopping cart with no explanation. Go figure.

How do you like the 40 grit (diablo)? Does it leave a spray-paintable surface or does it require a finer grit to remove sanding scratches.

I haven't tried it yet. I just bought it because my previous disk is wearing thin. It should be a beast on a project that I have coming soon. I can tell you that I prefer the Dewalt hard rocks over the Diablo. The Diablos just aren't as good. And don't cut as cleanly.
That would have been a steal. Here's why they did it:
https://www.amazon.com/gp/aw/d/B003O9MV ... flap+discs
You should send them a nice little note letting them know that you're gonna report them to the FTC for false advertizing if they do not send your discs for the agreed upon price. They can't erase their internet tracks and a $50 loss will be the least of their worries at that point.

I use the Walter 40 grit flap discs. I also have some 60, 80, 120 discs. They are great and last a long time. As it gets worn down you just have to take off the orange plastic. This gives the edge back and it continues work great. There are three arrows which allow you to refresh the disc. Once the third arrow is gone and it's worn down there is essentially nothing left on the pad side. There are some great youtube videos which explain how these work to get the most life. I fell I get my monies worth and they are a great value. I bought some from harbor freight but they aren't the same as the Walters and don't last as long. Just my .02.

ttreb4 wrote:I use the Walter 40 grit flap discs. I also have some 60, 80, 120 discs. They are great and last a long time. As it gets worn down you just have to take off the orange plastic. This gives the edge back and it continues work great. There are three arrows which allow you to refresh the disc. Once the third arrow is gone and it's worn down there is essentially nothing left on the pad side. There are some great youtube videos which explain how these work to get the most life. I fell I get my monies worth and they are a great value. I bought some from harbor freight but they aren't the same as the Walters and don't last as long. Just my .02.

Is the disc you're talking about one of these?

We use mostly 40 grit flaps on finishing steel. Gives a nice shiny finish in the right hands with the lover's touch, but as they wear down (pretty quickly too, I might add) it is harder to get that smooth finish.

They might not look worn, but they fade off pretty darn quick.

For prep work, we often clean up with a cup wire wheel on a 5" grinder. Bigger jobs require a 9" setup. But if it's actual getting down to clean steel, then it's the flap disk, or grinder depending upon your requirements.

Final finish sometimes we use a 5" Velcro style sanding disk on the grinder. That gives a nice finish, but again, in the right hands.

Here is the only place I deal with any more http://www.lehighvalleyabrasives.com/

Their clean and strip disks http://www.lehighvalleyabrasives.com/co ... -cs4-5-crs will remove mill scale better than anything I have come across. And they do not remove a lot of base metal as a coarse flap disk might.

SAIT cutoff disks DO. I purchased some cutoff disks from Horrible Fright. One cut of a 2 x 2 x 1/8" angle iron and the 4 1/2" disk was about a 3" disk. The disk disappeared faster than the metal.

Checkout Lehigh Valley Abrasives. All of their products are great. You will not be disappointed.

Ken

p.s. I have no commercial interest in nor relationship with this company - other than being a long term satisfied customer.

If it's useful to anyone, I've heard good things about this operation:
http://www.lehighvalleyabrasives.com/

...altho I have not bought from them myself.

I was lucky enough to pickup 25 3M 60 grit flap disks for $50 some time ago on Ebay. They are some of the best I have used. They just seem to keep going. I have used the Walthers and they are great, but very expensive. I really like their cup brushes, like their flap disks they are renewable ( have a steel ring that you remove when they are worn down to renew the edges.)

I have used the Horrible Freight flaps, they don't last very long, but consider the source.

5" and 7" 3m cubitron 36 grit fiber disks are all we use at work and they rock. Way better than using flap wheels.


Sent from my iPhone using Tapatalk

5" and 7" 3m cubitron 36 grit fiber disks are all we use at work and they rock. Way better than using flap wheels.




Sent from my iPhone using Tapatalk

LtBadd wrote:

ttreb4 wrote:I use the Walter 40 grit flap discs. I also have some 60, 80, 120 discs. They are great and last a long time. As it gets worn down you just have to take off the orange plastic. This gives the edge back and it continues work great. There are three arrows which allow you to refresh the disc. Once the third arrow is gone and it's worn down there is essentially nothing left on the pad side. There are some great youtube videos which explain how these work to get the most life. I fell I get my monies worth and they are a great value. I bought some from harbor freight but they aren't the same as the Walters and don't last as long. Just my .02.

Is the disc you're talking about one of these?

Yes I use the endure flex. 40 grit for taking heavy rust and grinding. I use 120 for taking off light mill scale without getting into the metal.

My experience with flap discs is to stick with the best ones......which naturally cost more, however they seem to last much longer and take more abuse.....which means you likely get more grinding, blending, etc. per dollar spent. The two that are superior in my applications are made by Pferd , and the Metabo brand flap discs. When you compare these two they look almost identical......I suspect they may be made in the same place.

Just like with plasma cutters and consumables....the lowest purchase price does not get the lowest operating cost!

Jim Colt

Many thanks for everyone's input.

I ended up getting a ten-pack of 5" 40g tigerpaw discs for $23. They worked great on a wrought iron job I did last week adding 50 intermediate pickets to a railing to make it kid safe. One disc removed all the paint for welding and still has a lot of life left. I used my variable speed 5" Bosch at a medium speed. The 40 grit worked great as my previous discs were 60g, old, and glazed. Customer was pleased and I made good money.

Pic shows old discs I had been using center and left with new discs right and on grinder. That's my old high speed grinder. A couple of the new discs were out-of-round and worthless.

Just another comment on those Harbor Freight discs, I've bought a couple of those assortment packs now and was pleasantly surprised with how they did. They lasted as long as any other ones I've ever used. And oh so cheap.

i only buy one grit and thats 40 grit i put all my old disc in a box and use the old ones to polish the metal and the new ones to take off metal .by the time i throw them away they are used up to the max.

I have a rubber or plastic backer for my Milwaukee angle grinder and some sand paper discs. From the contractor supply store down the street, I can get the sand paper discs for .10 cents if I buy 10 or more. Any grit. Attaches to the backer with a set type bolt, which holds down the backer and disc. I take the weld down with a regular grinding wheel, and detail with a sander disc. Easy and cheap!!!

I used to work at a place where we used those sanding discs for almost everything. They even bought a cutter that looked like a can opener. You could cut down an old used 6inch disc and turn it into a new 4 inch disc.

For the heavy hogging I use the 4o grit Pro Point 41/2in flap disk from Princess Auto ( The Canadian Harbour Freight ) and the 60 grit Abmast for cleanup if needed. These are both zirconia grit - cut like crazy and wear very well. If I need to fuss up a bit for paint I give a quick touch up with cheapo 120 grit aluminum oxide disks I pick up at the local Dollar store. They wouldn't last long for production work but as metal working is just a hobby for me they do just fine. Have Fun.

I have found 9x out of 10 you get exactly what you pay for. A local company has these made with their name on it from a small manufacturer. They are not cheap, but a little less expensive than the big name brands and last just as long if not longer.
http://www.jiscodirect.com/index.html
I buy their jumbo flap discs in 40 mostly, 80 if I'm polishing up SS.
I will also only buy Carborundum Gold 6" cut off wheels, don't chatter or wander when you start, cut fast, don't chunk, and last all day, and they don't come apart no matter what you do to them. I've seen too many people get hurt from cheap cut off wheels.