I have found that as with a lot of tools and widgets. Its the
advertising suggestion. And our minds way of picking the easy/first
thing that we thing will work. They look so good and the written
description makes you want to believe!
the holding power(only under ideal conditions) to the work surfaces.
The bench space not wasted(a false sense of space saving) Having
more benches piled with stuff that should have could have been put
away. And economy(because they are cheaper than the bolt downs. After
45 years in all manner of shops, studios and fabricating area's I
should know better but still get suckered in for stuff. Cold heat
soldering iron, Tip broke with in 3 minutes of the first time I
started using it, new from radio shack 9.95. Still looking for some
one living under a rock to buy it.
A vise with only the clamping part bolted to the bench made by vise
grip a couple of years ago was touted as the greatest thing since
sliced bread and bottled milk. It would have been a great idea if it
would have only worked. for large, off sized items. Would release at
any time it felt like it. would not secure the item if it held, due
to the composite plastic used in it make up. Plus they never seemed
to carry thru with all the stuff they had planned to make the vise
the most important tool in the shop.
I will say that the vacuum vises have a place if you need a light
hold on something in an area that you can't have a bolt or clamp on
vise. I had a 2 inch vacuum vise that I used for model making, I will
say that the clamp on vises are much better at holding things and
clamped to a bench or table.
If you want to protect the table top cut a strip of cardboard, sheet
felt( furniture slides) or rubber sheet material and glue it to the
clamp and bottom of the vise.
I have a number of sizes of the clamp ons and they work good. I had
one that was mounted on a trailer hitch mount that went in to the
receiver on the truck. It worked good out at places when you didn't
have a third arm to hold things.
Bottom line is that alot of stuff looks good in the package but
doesn't work out well when the wrapper comes off.
Sort of like book covers, music covers, video covers and software.
When you can only make a decision only on what you can see and read,
you probably will be dissapointed.
been there, bought that, and do ya wa na buy it!