Grinding machine for removing welds on steel weldments?
Close
Login to Your Account
Page 1 of 2 12 LastLast
Results 1 to 20 of 33
  1. #1
    Join Date
    May 2013
    Location
    Illinois
    Posts
    558
    Post Thanks / Like
    Likes (Given)
    12
    Likes (Received)
    158

    Default Grinding machine for removing welds on steel weldments?

    Is there anything like this that exists? Here's a picture of a product we make:

    20190916_101530.jpg

    Flap discs and grinding wheels just take too much time. I've been able to speed up the cutting process and the fit up/welding process on these, but the grinding is just something I can't seem to come up with anything. The grinding on these can easily take 2-3 hours for a set. I would love to find a machine where I could drop these in, have it knock down the welds to almost flush, then go through and blend in by hand.

    The picture above is just one example, there's 70+ different shapes and configurations we make, the ones in the picture are just the most complicated. We make displays and furniture products, those are table legs in the picture. Most products are painted or powder coated after completion.

    My first thought was a Blanchard type grinder, but I've never operated one, so I don't know how long they take or what their cost-to-operate looks like, or if this would even be a good application for that type of machine. Thoughts? Or just stick with the tried and true hand grinding method.

  2. #2
    Join Date
    Mar 2009
    Location
    Eureka, CA
    Posts
    3,900
    Post Thanks / Like
    Likes (Given)
    811
    Likes (Received)
    1409

    Default

    The very first idea to pop into my feeble mind would be a stroke sander with an aggressive belt. You could apply sanding pressure to weld bead areas and avoid areas that need no sanding/grinding.

    Shop Tools and Machinery at Grizzly.com

    AND...YouTube

    Stuart
    Last edited by atomarc; 02-27-2020 at 03:31 PM.

  3. #3
    Join Date
    Oct 2005
    Country
    UNITED STATES
    State/Province
    Pennsylvania
    Posts
    17,197
    Post Thanks / Like

    Default

    What's your budget ?

    yeah I know, your poor....BTDT

    Timesaver conveyor belt sander ?

  4. #4
    Join Date
    Jun 2016
    Country
    UNITED STATES
    State/Province
    New York
    Posts
    1,887
    Post Thanks / Like
    Likes (Given)
    1220
    Likes (Received)
    898

    Default

    GTAW (TIG) weld, less grinding. yea I know, prob not gonna happen.

    No blanchard grinding wouldn’t be good, not at all. The alignment of welded stuff like that is not good enough to allow it, and the machine would be enormous.

    Cubitron 11 is all you need to know.

  5. #5
    Join Date
    May 2013
    Location
    Illinois
    Posts
    558
    Post Thanks / Like
    Likes (Given)
    12
    Likes (Received)
    158

    Default

    Quote Originally Posted by digger doug View Post
    What's your budget ?

    yeah I know, your poor....BTDT

    Timesaver conveyor belt sander ?
    I have a Timesaver, 36" W, 2 heads, NC controls, wet model. It doesn't work as well as you would think, even with Cubitron II 60+ grit belts. We use it mainly for polishing stainless, so it could be because the roller is too soft. It's been a while since the contact roller was redressed, but I seem to remember going a little harder than recommended on it so we could easily rip through the pits on the mill finish stainless bar stock. I want to say its around 70 duro? It also requires the welds on one side of the leg to be mostly ground down, otherwise the welds on the conveyor belt side of the machine can really mess up the machine. Don't ask me how I know.

  6. Likes sfriedberg liked this post
  7. #6
    Join Date
    May 2011
    Country
    UNITED STATES
    State/Province
    New Jersey
    Posts
    638
    Post Thanks / Like
    Likes (Given)
    14
    Likes (Received)
    217

    Default

    Dynafile makes contact wheel with a 1/32" riser wheel so you can be aggressive at first then smooth it out. I haven't used it myself though

    Sent from my SM-G960U using Tapatalk

  8. #7
    Join Date
    Oct 2013
    Location
    The Gorge, Oregon
    Posts
    181
    Post Thanks / Like
    Likes (Given)
    37
    Likes (Received)
    138

    Default

    If your going to paint or powder coat, could you weld with an undercut then use filler that is powder coat comparable? If that’s not possible, weld with undercut, fill the rest with brazing. You could then knock the brass down with a router with a carbide bit. Is it the perfection you are looking for with metal finishing? Probably not. But, it is a way to speed up production. Now some good folks will say this is a “Hack” way to do this. How many milling machines and lathes were built with filler to the castings?
    Last edited by Flail; 02-27-2020 at 12:23 PM. Reason: Kain’t tipe

  9. #8
    Join Date
    Jan 2011
    Location
    BFE Nevada/San Marcos Tx
    Posts
    1,360
    Post Thanks / Like
    Likes (Given)
    1370
    Likes (Received)
    750

    Default

    We typically use machines called Pablo and Juan, only need to rent them by the day.

  10. Likes atomarc liked this post
  11. #9
    Join Date
    Oct 2005
    Country
    UNITED STATES
    State/Province
    Pennsylvania
    Posts
    17,197
    Post Thanks / Like

    Default

    Quote Originally Posted by Econdron View Post
    I have a Timesaver, 36" W, 2 heads, NC controls, wet model. It doesn't work as well as you would think, even with Cubitron II 60+ grit belts. We use it mainly for polishing stainless, so it could be because the roller is too soft. It's been a while since the contact roller was redressed, but I seem to remember going a little harder than recommended on it so we could easily rip through the pits on the mill finish stainless bar stock. I want to say its around 70 duro? It also requires the welds on one side of the leg to be mostly ground down, otherwise the welds on the conveyor belt side of the machine can really mess up the machine. Don't ask me how I know.
    Gee, I don't keep up on your soap opera.

    Might have tried listing in the OP what you have already tried eh ?..

  12. #10
    Join Date
    Jul 2006
    Location
    Hillsboro, New Hampshire
    Posts
    8,833
    Post Thanks / Like
    Likes (Given)
    2126
    Likes (Received)
    6118

    Default

    Heck, just go to brazed joints. Plenty strong, easy to control, easy to blend down when needed or build up again. I'd presume your fitment is pretty good to start, so that shouldn't be an issue. If you need more heat, TIG braze.

  13. Likes tim9lives liked this post
  14. #11
    Join Date
    Jan 2017
    Country
    UNITED STATES
    State/Province
    Washington
    Posts
    340
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    133

    Default

    Quote Originally Posted by cyanidekid View Post
    GTAW (TIG) weld, less grinding. yea I know, prob not gonna happen.
    +1 on TIG welding it. If you have the skill, you can even have a model where you leave the welds on there and charge the same price as the polished ones.
    If you’re grinding flat and polishing, then the weld prep needed for TIG isn’t an issue. The decreased productivity will be greatly offset by the decreased grinding time. But you need more skill for TIG welding.

  15. Likes cyanidekid liked this post
  16. #12
    Join Date
    Jan 2005
    Location
    The Netherlands
    Posts
    5,958
    Post Thanks / Like
    Likes (Given)
    287
    Likes (Received)
    1585

    Default

    Get a bigger angle grinder FGS
    One with 230mm discs
    And put pressure on it
    Also get a good disc The ones that wear quick work the best in general

    Peter

  17. #13
    Join Date
    May 2019
    Country
    UNITED STATES
    State/Province
    Michigan
    Posts
    607
    Post Thanks / Like
    Likes (Given)
    43
    Likes (Received)
    218

    Default

    Use a 9" angle grinder with a 3M Cubitron II fiber disc 36 grit (the really thin ones on a backup pad). The heat from the spark stream feels like lava when you're getting at it.

  18. #14
    Join Date
    May 2019
    Country
    UNITED STATES
    State/Province
    Michigan
    Posts
    607
    Post Thanks / Like
    Likes (Given)
    43
    Likes (Received)
    218

    Default

    Also, don't be afraid to change them out when they start to wear down. The lost time and increased fatigue aren't worth it.

  19. #15
    Join Date
    Dec 2016
    Country
    UNITED STATES
    State/Province
    Arizona
    Posts
    231
    Post Thanks / Like
    Likes (Given)
    107
    Likes (Received)
    133

    Default

    Can you show us a picture of what these look like before the welds are blended to get a better idea of what you are up against? I would think that 2 hours from welds to fully blended smooth part is not excessively long depending on the finish required of the final part. If it takes 2 hours to blend all the seams out I also think that the two flat sides are only 1/3 of that time at most, and replacing that portion with another process wouldn't add much benefit.

    What abrasives are you using, but more importantly how often are you changing them out? If you are blending both of those two parts with 1 80 grit flap disc that is why it is taking 3hrs. Abrasives are expensive, but the time is worth a good bit more so I change them out frequently when doing this type of work.

    I would MIG this, then blend with Sanding disc - Flap disc - DA sander in that order. (inside fillets run a clean bead so no sanding is needed) TIG would be more pleasant for whoever is doing the work, but I don't believe it is an efficient use here and wouldn't save any time over all.

  20. Likes Fish On liked this post
  21. #16
    Join Date
    Dec 2012
    Country
    AUSTRALIA
    Posts
    2,824
    Post Thanks / Like
    Likes (Given)
    12
    Likes (Received)
    908

    Default

    You need better welders...I seen all this---lay on a fat bead so there are no "Tram Tracks" when its ground,grinding excess weld off takes ages.......Find a welder who can run a decent flat weld bead with zero undercut.

  22. Likes Limy Sami liked this post
  23. #17
    Join Date
    Nov 2008
    Location
    Madera county california usa
    Posts
    2,528
    Post Thanks / Like
    Likes (Given)
    21
    Likes (Received)
    638

    Default

    Given these do not seem to be life supporting structural then the material should be prepped such that the full weld is still lower than flush.

    Proper V cuts at mating parts with correct wire size and speed should mitigate most of your problems.

    If the V allows for full thickness of material to be seen before welding then the weld will easily be almost same thickness of the material without being above it.

    Requires a good skill set welder as well as proper preparation and fixtures to hold it.

    Time better spent doing it such to not need to remove as much material.


    Simple puddle welding with oxy torch would do it but slow.

    Another vote for tig

    Sent from my SAMSUNG-SM-G930A using Tapatalk

  24. Likes camscan liked this post
  25. #18
    Join Date
    Oct 2012
    Location
    Albany Ny USA
    Posts
    433
    Post Thanks / Like
    Likes (Given)
    1507
    Likes (Received)
    209

    Default

    Get better abrasives. Buy disks (hard stone or paper) made for stainless, they are tougher and they hold up longer on normal steel. They also grind quicker.
    With proper abrasives, I could sand that weldment flush in around 5-8 minutes or less...
    I would also likely want to have 2 grinders, one with a quick removal and one with a finishing setup.
    They make disks ( the name escapes me) that are a flapper wheel style disk that have (I think) a 120 grit abrasive and various types of scotch brite style pads layered on top of each other. They were awesome at finishing stainless/steel and you could damn near do the whole job in a timely fashion on aluminium, rough weld to finish ready for paint in around 30-90 seconds... The life of the disk was shorter on the aluminum welds but they were still worth it.
    Second, get better at MIG. That is not a part that is worth the effort of TIG, its too big. Just get your joint setup and process dialed in to just barely fill to the toes of the weld with a slight crown at the center. The right abrasive will make the crown at the center disappear in seconds and blend into the base metal shortly after without effort.

  26. #19
    Join Date
    Oct 2014
    Country
    CANADA
    State/Province
    Ontario
    Posts
    1,378
    Post Thanks / Like
    Likes (Given)
    891
    Likes (Received)
    1140

    Default

    Maybe try putting 'skids' on either side of a handheld belt sander so that when it's sitting on a flat surface it doesn't quite touch the surface...

    That way you can put the skids on either side of the weld line and apply as much pressure as you like to get it close to flat without worrying about gouging the underlying steel!

  27. #20
    Join Date
    Mar 2011
    Location
    Providence RI
    Posts
    323
    Post Thanks / Like
    Likes (Given)
    73
    Likes (Received)
    46

    Default

    A stroke sander with a hard contact wheel and then a flat platen might get you part way, but you are looking at a 5k-10k machine if you can find one used (with the contact wheel) or 20k new. Most of the used stroke sanders out there don’t have the contact wheel option so make sure you can mount one if you find a cheaper used one.

    We dress welds like these for similar items and use cubitron II fiber disks in 36, 80, and a 3m pale blue “cut and polish” scotchbrite disk made for powder coating prep. Hit me up and I’ll send you one to try out.

    Unfortunately there is not simple solution. Getting your guys to used the correct abrasive and lean into the grinder is where it at. I know everyone recommends big 7-9” grinders but they are way to heavy and large to use for 8 hours a day and not have shity results. Set up your grinding station with dedicated grinders for each grit.

    Are you pre finishing sections prior to fully welding. Simple work holding can help too we use engine stands, it allows the legs to be flipped easily.




    Sent from my iPhone using Tapatalk


Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •