Burnishers

[sam]

Not crazy about shelling out 30 bucks for a burnisher, but I'm wondering if a burnisher does a much better job getting the hook on a card scraper than the round end of a file.

Thanks,

s

[Phisherman]

An old piston rod makes a nice burnisher.

[Dave Balderstone]

You can use the shank of a screwdriver, but:

$7.50 CAD

[Ed Pawlowski]

Round shaft of a screwdriver works if it is smooth.

[Doug Miller]

I think you mean a push rod... a piston rod would be a little unwieldy.

[Doug Miller]

I went to a local engine-rebuilding shop and bought a few old push rods for a dollar apiece. Chucked one in the drill press and polished it with successively finer grits of sandpaper, ending at about 800 or 1000. I've been burnishing my scrapers with that for seven or eight years now. Works just fine, and beats heck out of spending $30.

[Ed Pawlowski]

You're supposed to take it out of the engine?

[Leon]

I am thinkin you may mean push rod rather than connecting rod.

[Ed Edelenbos]

Tough call... ??? 5$ for the rod and then 2 hrs to polish, I guess if those 2 hrs are worth less than $12.50 each...

[-MIKE-]

I heard high carbon steel drill bits work, too.

[sam]

My question: will an actual burnisher do a much better job?

Thanks,

s

[Maxwell Lol]

Some use the shank of a chisel.... That's what Tage Frid suggests in his books...

[Maxwell Lol]

I think the real issue is can you control the angle of the burnisher in a consistant manner, and put enough pressure to form the hook?

As I said, the Tage Frid book (Vol. 1) has a section on the scraper, and he uses the shank of a small chisel (AIR).

Clamp it in a vise, and bear down, maintaining the angle during the hook forming.

My trouble is, I am not sure if I am forming a 5 degree hook consistently. I can do it once, but if I come back months later, and want to touch it up, can I duplicate the same angle? Is it 5 degrees?

10?

You may wish to consiter the Veritas variable burnisher.

lets you set the degree of a hook you want. That way you can have scrapers, with light, medium, and and heavy degrees of hoo - consistently.

[dadiOH]

No. Assuming the alternative used is smooth.

[RonB]

As has been pointed out here, lots of things will work. In addition to screwdrivers and chisels, I have even used a large nail or spike.

[J. Clarke]

Anything that is smooth, approximately round, and harder than the scraper will work. The burnisher is handy because it has a nice handle and a good length all of which is usable but there's nothing magic about it. I've used drill bits, chisels, and screwdrivers and they all work fine but they're harder to hold or have less working length than the purpose-made burnisher and with the chisels you have an additional sharp edge to avoid.

So, no, it does't make a better hook, but it's a more pleasant tool to handle for that particular purpose.

By the way, Amazon has "crown" brand burnishers, which work fine, for 15 bucks and shipping right now.

[Jim Weisgram]

[...snip...]

2 hours? I think that would be a 5 minute job...?

Now getting to the machine shop and back, depending on where you live, that might take some real time.

[Larry Jaques]

On Wed, 2 Dec 2009 00:33:04 -0600, the infamous sam scrawled the following:

Compared to a hardened screwdriver, no. Essentially, anything harder than the scraper alloy will be able to turn a hook.

I prefer a plain old honed edge to a hook, but I'm not using scrapers every day, either.

Use whatever you like. Try some things and figure it out for yourself, Sam.

-- Follow the path of the unsafe, independent thinker. Expose your ideas to the dangers of controversy. Speak your mind and fear less the label of 'crackpot' than the stigma of conformity. And on issues that seem important to you, stand up and be counted at any cost. -- Thomas J. Watson

[scritch]

If you leave it in, and rev up the engine, you don't have to move the burnisher back and forth, just slide your scaper back and forth across the pushrod.

[whit3rd]

I've used a screwdriver shaft (go for one that isn't nickel-plated, from a good quality screwdriver), and tungsten carbide rods and rounds, and there isn't much reason to prefer one over the other.

A favorite old crosspoint screwdriver with a bunged-up tip can do this in retirement. Use that resource!

You want a hardened rod, so I'd think a valve stem or a shockabsorber shaft would be better than a pushrod.