Engraving brass...alloys?

[Scota4570]

I broke out my engraving gear and did three practice  plates using sheet brass glued to wood.  IT is K&S 0.010" sheet glued to wood.  The practice plates were acceptable to me.  I used a 95* graver made using Lindsay templates sharpened to 2000 grit.  I am using a lindsay pneumatic tool. 

When I did the patchbox lid, it looked terrible.  THe graver did not run smoothly.  The lines were ragged.  I had a hard time following the lines.  I have a new patchbox on order.  This is the Vincent patchbox as sold by track. 

Is it common for different brass alloys to engrave differently?  Maybe the patchbox lid is a "gummy" alloy that does not cut smoothly?   

I have a 75* and a 105* gravers ready to go.  This is a tiny pattern should I use the 75* next time?



BTW, using waterslide decals was a bust.  THe decal does not stick well enough and it comes up in hunks when engraving.  Printing with an inkjet jet on kitchen parchment paper does work.  THe ink is water soluble.  IT transfers to a white lacquer or china white background just fine.  IT works best when the print is fresh.  IF the print is old breathing on it makes it wet enough to transfer.  The ink beads up on the parchment but not enough to cause a problem.   

[Kingsburyarms]

I have had to anneal Brass to get a sharper cut for engraving, maybe test it on the back side of a piece, and if too soft - harden it. a 75 should be fine with a Lindsay.

[D. Taylor Sapergia]

It doesn't take much to damage the point on a graver.  That most likely, is the reason for your difficulty.  Just re-sharpen and give it another go.  I love my GRS rotary lap for precise repeatability.

[T*O*F]

When I did the patchbox lid, it looked terrible.  THe graver did not run smoothly.  The lines were ragged.  I had a hard time following the lines. 

If the lid is curved and not totally supported, you will get vibration which will cause that problem.  It needs to be solidly backed, perhaps with Bondo.  Just gluing it to a block of wood won't do it.

Is it common for different brass alloys to engrave differently?  Maybe the patchbox lid is a "gummy" alloy that does not cut smoothly?

Yes, but that's probably not your problem.  Brass needs to be engraved at a lower angle so it doesn't plow.  Try a 40 or 45 degree face.  They will shear better.  Also, brass has a tendency to transfer to the point.  Take a bottle cap lid or old film canister and put a couple of cotton balls in it.  Put a few drops of 3 in 1 oil on the balls so they are damp but not wet.  Poke your graver point into it every few minutes.  It will cut far easier.  Historically, oil of wintergreen was used for this, but some people are allergic to it.

[Scota4570]

"Brass needs to be engraved at a lower angle so it doesn't plow.  Try a 40 or 45 degree face."

Seems to have helped.  Akin to modifying the point angle on a drill bit for soft material.  It seems more controllable now.   This is my first try with the different tool angle and lube.  Still a bit ugly but much better. 


Thank you.

Scot

[BillF/TRF]

Looks good to me!  I am at about the same point but still working on practice plates with chase hammer and graver.  Your lines curve smoothly and your scrolls and lobes look good.  For me it takes a lot of practice, especially if you are moving around and continuously turning and locking a gunmakers vise while trying to get that "even width" line into a nicely  rounded scroll.  Keep us posted!

[Scota4570]

I gave up on a regular vice right away. 

I made a "ball" out of a large lead casting, a turned wood receiver, a drill press vice, and a lazy susan (last picture).  The large piece of lead was cast in a salad bowl and weighs about 50#.  It has enough inertia to resist turning while engraving with a hammer and graver.  It turns with a push of the hand. 

The other contraption is the "Ball" I use now.  It is a smaller 10# piece of  lead.  Same lazy susan.  The vice is smaller.   I can rotate it by hand 360* while cutting a line.

 I think I want a smaller diameter post so I can rotate the work more smoothly.    I might try a front wheel bearing off a car. 

[Ron Scott]

I just finished  engraving  a side plate , toe plate and parch box on brass using the Lindsay 96 degree angle  graver. I used the standard 45 degree face, (which is the white plastic measuring spacer from Lindsay).  A suggestion that might help is to put very fine surface on both the  graver face and heels. I have some of the fine grit material sold for sharpening  chisels and plane irons.  Lindsay sells it as well as several of the woodworking catalogs. You get a mirror finish with these after sharpening with the 1200 grit diamond stone. I feel that the polished graver glides better without as much as the sticky feel. I was able to cut the sheet brass for several hours without dulling or breaking a point.  Consistency in the rotation of your vice will help with smooth curves. Anything you can do to make that smooth will help.

[Goo]

Sometimes you don't. get the same kind of brass with purchased  pre made rifle parts as you do with sheet brass.   Sometimes the sheet brass is annealed sometimes 1/2 hard sometimes the parts you buy from suppliers are bronze and not brass.   It all cuts differently you can't just just know unless you take the parts to be shot with an alloy laser testor like they have at the scrap buyer to see the alloy's composition. Or you can buy two patch boxes so there is an extra one to practice on,.  Or you can practice on the back side of the part once inlet no one will ever know.  In any event there are lots of variables to interfere with your efforts.