What makes the Biax scraper so "unique"

I am certain I am not the first to ask this question.
What makes these units so special? The air unit seems to be nothing more than an air chisel. And the electric unit reminds me of a saws all....

They are designed for scraping and the only machine in production in the world that does it...

That is what makes them special...

It got popular when we were still two hands and shoulder holding, hand bumping and pushing our home made best scraping solution to go frosting and flaking Cs an Ds.. and when we found it better than ours it stayed.

and the only machine in production in the world that does it...

Click to expand...

Only one of two!
The Renz scraper is quite similar, but way cheaper. Worked with one and had nothing against it.


Nick

I know two people with Renz scrapers in Melbourne, Australia. I've used one of them and it feels pretty well identical to the Biax I tried on the same day.

My own Aldi variable speed recipro saw adaptation which I call "Aldix" is not quite as good, too light and too much play in the blade guide, but I've used it a lot over the past 4 years and its still going well....
Cheers,
Joe

Nick Mueller said:

Only one of two!
The Renz scraper is quite similar, but way cheaper. Worked with one and had nothing against it.


Nick

Click to expand...

If everyone is putting in their opinion, here's mine.
A small history lesson:
I used my first BIAX in 1972 and have worked with DAPRA since 1984 as their go to instructor and customer service rep. If the sales department can't answer a customers question on what unit or blades to buy they give the customer my email or phone number.

Rudy Wetzel of Wetzel Tool who was co inventor of the first light-weight power scraper, the BIAX. When he passed his daughter changed the name to DAPRA Corporation by using her husband name Dave Pratt.

Anderson made a heavy-duty portable power scraper, I would guess in the early 1940's. I used to own one and it was what I would call a hand held power shaper. It is pictured in the Connelly book and someone on You Tube shows one. I wish I still owned it.

I have tested 2 Renz Biax copies, one at a US Army Depot and one at a Navy shipyard. I tested them for about 30 minutes each. The blade length adjustment screw and blade holder were not well thought out. IMHO a Rentz is a waste of money, time and effort. If someone offered to give me one, I would say no thanks. They were in like new condition as the "scraper-hands" in both places never used them and preferred the BIAX.

I own 7 BIAX Scrapers and 1 BIAX 1/2 moon flaker. Home-made Saw-Zil scrapers...No Comment. Rich

bmikkalson said:

What makes these units so special? The air unit seems to be nothing more than an air chisel. And the electric unit reminds me of a saws all....

Click to expand...

I guess they are not unique, given the Renz scraper. . you sometimes see large stationary ones come up as well - ie they'd be a 'work station' with the scraper supported by a pole and balanced. Sounds appealing after slugging one for a while.

They and air chisel and the sawsall have reciprocating motion. That's about where the similarities stop. There is a solidness and smoothness to the biax that is nothing like these other tools. They are built to be used constantly for years. A busy contractor using a sawsall is going to use it what, 1% of the time if that - and he doesn't expect it to last years. He's also using it infrequently enough that a bit of shake rattle and roll doesn't matter....the guy scraping is holding on to it for hours/days and it does matter. Think of going down a hill in a soap box vs a 911.

Why scraping works is the control and consistent depth of cut, can be less than a tenth. You need consistent smooth motion to get that control. Just my view after having used all three. biax's. sawsalls and cold chisels.

There's been talk guys trying to build them out of sawsalls. I have not heard of a successful completion and as per above always thought these well intentioned endeavors doomed. There is no reason though that an enterprising person could not build a comparable device from scratch.....but unless someone really wanted to its a huge stack of hours against the cost of a used biax

Figure out how to get a test drive and what I'm saying will hopefully make more sense

Mcgyver said:

.....
There's been talk guys trying to build them out of sawsalls. I have not heard of a successful completion and as per above always thought these well intentioned endeavors doomed. ....

Click to expand...

There are at least 4 people I know of who have converted recipro saws successfully - and are ujsing them regularly.....
No way would I compare mine with a Biax, but I can't afford a Biax at nearly $1000 for the cheast one in the past year or two.
It took me about 3 hours to do the conversion - following the information from right here http://www.practicalmachinist.com/v...onvert-makita-hk0500-metal-161099/#post925900

Here is mine in action (note the ancient Biax on the bench next to me - I DID have a direct comparison that day):

that looks like it worked out well for you. you say 'no way you'd compare...' Since you've used both, can you comment on why?

Thanks Mcgyver.
As I mentioned in Post #5, it is a little lighter than the Biax and as a result jars your arm a bit easier if it catches anything - even gently. The slide for the blade is nowhere near as solid as the Biax ones and as a result it isn't as easy to position accurately. The blade sort of wobbles a bit, maybe 20 thou or so in all directions.
The guide has also worn a bit since I made it 3 years ago. I doubt that a Biax would wear much in decades.
Lastly, unlike Mike (holescreek) and Stuart (Stustoys), I didn't make the stroke adjustable. I initially set it to about 12mm which was way too long and then modified it to about 4mm which is fine for spotting but a bit tedious for roughing. I had intended to make another one - and maybe will one day, unless a Biax comes along - and have the second one set at 8mm stroke.
If I ever wear the thing out, I'll probably follow the example of Mike or Stuart (who made his externally adjustable!) and make an adjustable one.
Anyway, I love power scrapers of all kinds just because you can do so much work so quickly. I still use hand scrapers for spotting and for scraping against steps or into dovetails of course.
The current project is a 1940s Cash horizontal mill made in Melbourne Australia, the last one was a Brown and Sharpe No2L surface grinder from about 1935. Before that I scraped a CC tool and Cutter grinder (probably from the 30s) and the next project is a Van Norman No2 cylindrical grinder from 1925....
So much scraping, so little time

If anyone ever comes across a 'dead' Biax, PLEASE let me know - even an old one with stripped gears or a burnt out motor! I think that's the only kind I can afford...

Cheers,
Joe

Looking at the You Tube...I can say "Bock Bock Bockkkkkkkk"........my students know what that means.......lol

Some good ingenuity being shown here and I am thankful to all for sharing. Like so many other things in life, we often have to make due with less than we desire. In the US we do sometimes get a bit complacent about how many resources we can choose from that others in the world do without. The availability of these scapers on the used market is one of them. They dont come up that often but when the do it would seem from the other options here to be real bargains. Of course nothing is a bargain if you dont have the money when they are available.

This was a good question to ask thank you Bmikkalson for asking.

Charles

I just add a picture of a (my) Renz scraper:


(I think the leather strap is not original)

I used a Biax only once and cant (with my limited experience) realy find a difference in use.

When talking with somebody about scraping I almost always refer to "Biax", I think it has become something like a synonym

Stefan

Nice tool. And waaay more affordable than a Biax. I wonder who supplies Renz with the motor unit...could be Bosch as well as Fein.

Mauro

Ben will get his hands on a BIAX later this month as he is hosting the St. Paul, MN Scraping Class. We still have room if anyone wants to come. Rich

I wonder who supplies Renz with the motor unit...could be Bosch as well as Fein.

Click to expand...

Pretty sure that its a Fein motor.

Stefan

Richard King said:

Looking at the You Tube...I can say "Bock Bock Bockkkkkkkk"........my students know what that means.......lol

Click to expand...

I can even tell you what that means. Chicken scratches, and I've never shook your hand. True the You Tube is basically wiping off the blue.

That vid was shot in my shop. That was 2 1/2 years ago, just as he was starting out. He's improved out of sight since. I've made him up some springy tips and a little relieved tip to do do dovetails. I've ground some of his slides

I had a play with that thing, it actually cuts if you lean on it. It's 15 -20% of a BIAX, but for $70 bucks. A Biax is a plus $4k buy down here. Joes is a retired health care worker, he would much rather be spending his money, on his grand kids.

We cant alienate these guy's that want to do a Biax job on an Aldi budget.

Best Regards.

Phil.

I made one a couple months ago. I took apart 3 of the better quality sawz alls I had and they where un-modifiable. Not like a shaper power transmission. I don't know what to call it. So I bought a 25$ HF saw. That saw was junk so the "scraper" I made with it is less than satisfying. I even soldered on a 3lb handle to add some weight. I have learned to move so much metal with my CI diamond hone a carbide scrapper I just use that.

machtool said:

....
That vid was shot in my shop. That was 2 1/2 years ago, just as he was starting out. He's improved out of sight since. I've made him up some springy tips and a little relieved tip to do do dovetails. I've ground some of his slides

I had a play with that thing, it actually cuts if you lean on it. It's 15 -20% of a BIAX, but for $70 bucks. A Biax is a plus $4k buy down here. Joes is a retired health care worker, he would much rather be spending his money, on his grand kids.

We cant alienate these guy's that want to do a Biax job on an Aldi budget.

Best Regards.

Phil.

Click to expand...

Thanks for the backing up Phil!
However, I think Richard just has a quirky sense of humour. I think he was just having some fun with me. I don't think he was trying to alienate me or Mike or Stu or anyone having a go.
You are right though: I spend a lot more money and time on 'toys' for the little boys than on my workshop. I think it is a better investment. I mentioned a bit on the WWF the effect it has had involving them in my workhop since they were toddlers:
That sort of thing will stand them in good stead in the future - and you can't get better returns on investment than that - not even on a brand new Biax (although I'd still love one.... one day maybe)
Cheers,
Joe

I have an Astro Pneumatic scraper that is designed for peeling of paint, gaskets, etc.
I don't know if it would be any good scraping iron but the price was about $40 so if anyone feels like trying one of those might be an alternative.