Is there harm in using a 3500rpm belt grinder?

Discussion in 'Restoration & Razor Making How-To's.....' started by Zipvex143258, Mar 6, 2012.

  1. I know that around 1750rpm are preferred, but would it be harmful to use the standard speed belt grinder of 3500 rpm? Any information is appreciated! Thanks.
     
  2. Hi Zipvex... Can I assume you are talking about a grinder/buffer (with wheels) or do you really mean a belt sander? I'm going to guess grinder due to the rpm reference and, if so, no there's really not a problem with that. The true aim is to buff and polish with a particular disk/wheel edge speed measured in surface feet per second. The polishing wheel or buff (or sometimes the compound packaging) will often recommend a speed. The speed is the result of the machine's rpms, of course, but you also have to factor in the wheel diameter (and its outside circumference). So, two grinders with the same rpm will have different surface (edge) speeds with different sized wheels/buffs. A 10-inch disc will have a much higher surface speed than will a 6 or 4 inch, at the same rpm speed. So, if you have a 3500 or 3600rpm machine and it burns or is too fast, try using a smaller diameter wheel in it. Hope that makes sense.
     
  3. Here ya go read through this. It gives you a SFM chart and how to change it up or down. If that link don't work search for caswell plating and find their polishing info guide. I sent this from my phone and I think it's a mobile link.
    https://www.caswellplating.com/buffman.htm
     
  4. Are you talking about a buffer/wheels or a belt grinder? What are your plans?
     
  5. Use 4" wheels and the surface velocity is much lower than a 6-8" one. That said, buffers can eat a blade up fast and ruin the temper.

    If you are talking grinder I think it depends. If you want a VFC control (I think that is what they are called, variable speed control) then I think a 3500 rpm motor is recommended. I have a 1750 rpm motor running my grinder, but I use a 3-step pulley to have 3 speeds.
     
  6. Thanks that is incredibly helpful I never thought of it like that.. Most videos I have seen or watched usually use a slower spinning bench grinder but always have a big wheel attached. It makes sense just to use a smaller wheel I appreciate it!
     
  7. I have a bench grinder and was looking to attached cotton buffing wheels to polish up some razors. I was worried about it spinning to fast and increasing the temperature of my razors too high. I don't want to mess with how they were tempered. As rossvtaylor said, I could use a smaller wheel to account for the faster motor.
     
  8. It will work. Just make sure you use a small will 2",3" or 4" wheel. Also be very careful. I have few different piece of equipment and to be honest, I feel like the buffer is one of the more dangerous one :)
     
  9. Thanks for the advice and yes I'm sure dangerous but I will lean to the side of caution. Used them a bunch before in the past but never for more than say a minute. From my little researched I've gathered is that i'll need to invest a couple hours into bad looking razor.
     
  10. I use a 3500 rpm grinder with 6" wheels with greaseless compounds for polishing and I have absolutely no issues. I clean until the blade seems warm to the touch and then dip in ice water to ensure no damage to the blade, dry with an old towel and repeat. It works beautifully and I have done no damage thus far. Good luck on you restos
     
  11. Thanks this is what I was looking for. Gotta pick up some greaseless compounds. I am thinking grit wise - 80, 120, 180, 240.. What do you think about that?
     
  12. Mike H

    Mike H Moderator Emeritus

    Have you seen Brad's videos in the Restoration Stickys?

     
    Last edited by a moderator: Feb 6, 2017
  13. It depends on the condition of the razor. If you need to remove pitting or deep rust issues, then start at 60-80 and move up from there in a progression. Every jump helps alleviate the prior grinders scratches. I have been lucky and most of the razors I have acquired have minor surface scratching and have needed nothing grittier than 120 or 240. If the razors are in good condition and need nothing more than good clean and polish, or if you want to maintain the original factory grinding (like the Sheffield type,) rouge may work best. I always finish with black rouge on a demin wheel, white rouge (jewelers rouge) on a cotton wheel, then Mother's mag and aluminum polish to get a good deep reflective shine. This is just my technique, and seeing as there are far better restoration guys here on B&B, keep an open mind to all of your options.
     
  14. These videos are the reason I was asking if it was possible to use a faster bench grinder believe it or not. What a great series of videos, and is probably the reason I am going to attempt it myself.
     
    Last edited by a moderator: Feb 6, 2017
  15. The more people that chime in the better =) I'm sure in time I will end up finding what works for me. Just looking for a good starting point and all info have been really helpful so far. Thanks.
     

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