I was back home in Minnesota for a couple weeks this summer, and being back home means I have access to all the tools in my dad’s huge truck shop. Much like using a rolling mill to texture metal (see post 172: Rolling Mill Textures for more information on that), I wanted to try out Dad’s 30-ton hydraulic press with laser cut templates.

This beast has been in the family for generations – it was in my grandpa’s truck shop before my dad’s.  It’s hand pumped, beat up, a bit oily and dirty, and perfect for experimenting on.  It was delightful working with Dad on a project, and introducing him to a new technique he’s never tried (or needed to honestly; truck parts generally don’t need this kind of treatment!)

Full disclaimer – this is the first time I’ve used a hydraulic press before, and I may not have all the terms correct.  This is my very simplistic understanding of it. There are a lot of great resources out there, and tons (ha ha) of classes taught by seasoned professionals if you want to know more! If you’ve never used a hydraulic press for making jewelry before, a key component is a Urethane pad. Urethane is a dense material that is kind of between a plastic and rubber. It’s necessary for compressing and pushing the metal up into the plate you want to texture, creating a more defined image. After reviewing the options available (and watching this informational video) I picked up a square Bonny Doon 95-Durometer Urethane from Rio Grande.

Other than the urethane pad, I had sheets of 22ga copper and a random assortment of patterns and shaped that we cut out on the laser from different materials.

Laser cut materials we used for templates:

• 1/8” cast acrylic – I didn’t like using it.  Too deep for the size holes I cut (they were way too detailed for that thickness) and it felt very brittle.
• 1/16” plastic sheet – This worked great for the bigger shapes, but I didn’t even try it on the smaller, detailed textures.  I was having too much fun with the next two materials.
• .025” plastic sheet – this material is great for stencils, and worked well to get nice texture.  It did get a little bit squashed and distorted slightly – you can see it slightly bowing in later images. 
• Cardstock – Simple, everyday cardstock, and I think it was my favorite to work with.  I could get 2-3 decent presses.

Trial 1: Anneal or not?

I know better, but I thought “Let’s try it without annealing first!” Annealing is basically the process where you heat up your metal so it becomes more malleable and can form better – we did it with the rolling mill experiment as well. 

The first pressing was of the quatrefoil shape, with 1/16” plastic. The unannealed pressing went okay, but the edges are soft and it really squished the points of the laser cut plastic.  (This is expected to happen eventually, but the hardness of the metal expedited the process.)  We re-pressed it with an annealed piece of copper, with the same plastic template, and it came out sharper.  It would have been even better with a fresh template.

We tried the unannealed copper with one of the textured plates – I forgot to photograph it, but it wasn’t really worth commenting on.  Anneal your metal!

Trial 2: Thickness of the texture plate

Now that I had annealing down, we thought we’d compare the pressing of two different thicknesses of the laser cut texture plates.  I chose the .025” plastic sheet and the paper for comparison, and was surprised at the volume the thinnest plastic sheet I used got.  Definitely more shine and dimensionality. 

Trial 3: Number of pressings

I found I preferred the cardstock for a good, but not totally distracting, texture.  After the first pressing, the cardstock still looked usable, so we pressed it again!   Unfortunately, the photos aren’t super great for this comparison, mostly because the surfaces annealed differently, and I didn’t have access to pickle to clean them up.  (I didn’t want to use more abrasive methods for consistency’s sake.)  The sootier looking copper is the first press, and the one with the cool oil slick like streak is the second press.  The second press does look a little softer, and the fine lines are thinner, but overall, I was impressed with the resiliency of that paper. 

After the second pressing, the edges fell off the lover’s links texture plate, but the center looked fine. So, I did a third experimental press, you can read about down below in Trial 5.

Trial 4: Smaller, more detailed stencils and placement

I had a couple small stencils I made up out of .025” plastic sheet for enameling that I threw in the mix while packing (You can see them in this Instagram post.) They were only 1.25” x 2”, compared to the bigger 2.75” square I used for the other pressings)  I cut the copper down to size as well, and they turned out SO GOOD.  I love them.   

I wanted to try it again.  So, we thought we would expedite the process and press both at the same time.  It’s all experimental, right?  Well, the second pressing, doing both at once, was less than impressive.  I had noticed that the pressing wasn’t always consistent across some of the bigger pieces, and here it was really evident.

I’m guessing that is why Bonny Doon makes their form boxes and die containers.  The box keeps the energy of the pressing force contained and working for you, rather than losing force out the sides.  And, honestly, I can’t guarantee the iron pieces we were working with were perfectly level either. Perhaps a seasoned professional can give an answer more than a guess!

Trial 5: Doubling up

Buoyed by our success, I thought, why not try pressing two laser cut templates overlapping?  Crazy, I know.  I carefully taped the lovers link paper pattern (which has been pressed 2 times by this point and was a little ratty around the edges) to a 1/16” semi-circle cut out.  It worked great, honestly, even with the paper on its last legs (I had to weed out each paper oval impressed into the metal – it had pretty much disintegrated).  It is a great avenue for more complex pieces!

Trial 6: Different top block

While we had been working, we had noticed that the iron block we were putting on top was not the smoothest.  They were salvaged metal pieces, used for keeping what every truck part or piece of metal dad was working on that day in place.  They had minor divots we didn’t even notice that became pronounced in the pressed copper.  So, as an alternative to try, Dad had a thick steel block with some smoother areas and a hole right in the middle of it. This is where we really saw the power of the hydraulic press.

We made our little press sandwich: An iron block topped with the urethane, the 22ga copper, a .025” lasered texture plate and this new block on top.  This urethane really wanted to do its work – the force of the press popped the plastic texture plate and the copper made a beautiful dome 3/8” deep at the hole; deeper than any of the plates that I even brought.  It looks really cool breaking out of the oval dot texture like that.  I don’t think either of us really thought about the power that was being contained by that top plate, but then again, people make all sorts of bracelets, rings and hollow forms on a hydraulic press. 

Recap thoughts and Lessons learned:

• Using the hydraulic press was very fun, and a great way to add dimensionality to your metal work!
• One thing I didn’t try was an engraved texture plate vs. one where the design was cut through.  I would expect it to work, but the laser engraved texture would be evident in the final piece, much like the texture of the dinged-up iron you can see on some of the pieces.  I wonder if they would hold up better, or if the pressure would make them disintegrate faster.
• Anneal your metal!
• Make sure your top plate, the material you are pressing your metal up into, is smooth.  Every tiny imperfection will show otherwise.