Automotive hydraulic die forming

Has anyone used the hydraulic presses used in the automotive
industry for forming metal for jewellery.

I used one of the small Harbor Freight ones for several years before
saving enough for the real thing. I broke it a couple of times and
had to have the frame repaired, too much stress. I also had to
replace the jack 3 times.

Donna in VA


Has anyone used the hydraulic presses used in the automotive
industry for forming metal for jewellery. 

I did.

I have not worked with the Bonny press, but seeing several pictures
and all the reading here. I made one using an automotive press which
I had already. First the metal pieces that come the automotive press
are not very useful. They are to big and shaped wrong to hold the
parts I was trying to press. Some will work but only as backup pieces
or top plates. Go to a good scrap yard and dig through the cast off
material. I found pieces of thick walled pipe, metal plate and solid
rod which I took home and cut up to make my dies and plates with.
From and industrial supply I found High density silicone rubber which
had very good compression characteristics and rubber pieces from a
junk yard, old car suspension. If you can find it use truck parts,
cars work, but truck is better. You get more rubber to work with and
it seems to have a higher compression value. I did not have luck with
tire side wall, the lines showed in the metal when something did work
and it took so much pressure it was starting to bend my cross bars
which threw off my caliper readings. Inner tube worked ok, but to
time consuming cutting all the pieces. Check with heavy equipment
places for the inner tube, a lot of farmers still use tubes in their
tires if you want to try it.

After you get your tooling together, you need some way to get
consistent results. I could not figure how to add a gauge to my jack,
so I used a electronic caliper touching the bottom plate attached to
the jack. I would extend the caliper (after touching the jack to the
form)up to the bottom of the jack. There is a rod that protrudes from
a caliper when you extend it, it is for measuring holes, but this
extension is also how I measure how much compression I have. I
increase pressure and check my results, then repeat until I get the
desire results. Record the numbers off the caliper each time you
test. When it finally comes out how you want, you will have the
numbers you need to repeat the process. Also record what you used to
compress with, I use several different materials and if I don’t put
it in my book I forget and the next time it won’t come out right.

Do not use fluids, no matter how well you think you can make
something, or how great the idea seems. If you do, let me know how
you did it and what you used. Also, I have not used over 26 gauge
plate, mostly 28 and 30.

One last thing, I have a little Asian lathe a 9X20 and a mini-mill.
Some forms I could not make without them, but mostly I can do with
roughed parts and inserts. Once you have a rough setup, you will be
surprised how much time you can consume with it trying different
things and materials. If you try copper anneal first, the plate that
comes out of the hobby stores is hardened.

Hope this gives you some ideas. The caliper or something similar is
the key to repeatability on this if you can’t get a gauge on your


Helen; The Bonnie Doon presses are hydraulic bottle jacks used for
lifting trucks. I come across plans to make you own press from time
to time perhaps someone here has them.

Dave Owen

You might want to try using a 4" plus diameter PVC pipe end caps.
Fill them with Devcon Flexane available from McMaster Carr or other
industrial supply places. Devcon is available in different durometer
ratings (softness) and you can make several with different ratings
and press your piece right into them. Mark them on the sides with
the ratings so you don’t get them mixed up. They all look the same.
Harbor Freight has these presses on sale regularly for under


They said it could not be done, but if you know what you are doing
it works just fine!

Let me explain:

I took the first deep draw course with Lee and Phil. Their press is
really very nice, but I did not want to spend all of those $$$. So I
bought a 40 ton press from Northern Tool. Since then my wife
(Jennifer) took a deep draw course and came back with a motor driven
BonnyDoon press. I had the dies made for it and both the BD and my
auto press work just fine. But there is a lot less work involved in
the motor driven press and there is a lot less guesswork involved.
If you are not at home with making tools, go with the BD press. If
you like challenges, the automotive press will work. Most of what we
do is deep draw, but the other functions will work on both presses
as long as you understand what you are doing.

Charles Friedman DDS
Ventura by the Sea

Here is the web site for boony doon’s web site.

One must have is the die forming book Hydraulic Die Forming for Jewelers and Metalsmiths

~Susan Kingsley it is listed new on amazon right now but you can get
it from some of the forums supporters or get a used copy. It is a
must The boony doon forum is also a must for the archives. As far as
using an A frame or H frame press. The ones from harbor freight type
stores. Are meant to be used with the size of jack that they are sold
with. I have a 20 ton unit that I converted to an air over hydraulic
jack. That works fine for what it is. you can’t put a larger jack in
and not have problems.

You will have to make adapters to hold your tooling to the press now
matter what kind of set up you make. Only if you are getting tooling
and a press from the same place with it be a put and run type of

The other thing is using scrap rubber and bits and pieces,can be a
bad deal lose of time ect experimenting. And then not being able to
find that exact thing next time you need it.

been there done that !

I am not a lawyer, and never played one on TV! All the usual and
standard disclaimers apply. Do not try this at home, use only as
directed, No warranties express or implied, for the intended use or
suggested uses, Wear safety glasses, closed course, professionals

You have to be very careful with tooling. PVC Pipe and pipe fittings
do not have enough strength to use as containment boxes. Even steel
parts will deform and can break under pressure. This can throw stuff
around the room- you do not want to be hit by any of this! Poorly
supported components will fail. When you put stuff under pressure you
store the energy which is released rapidly on a failure. The Cheap
automotive presses may be made of questionable materials and design
can be marginal. These can and some have failed. Even the Bonny Doone
tooling can fail if misused.

Using a power operated jack can be much more dangerous than a manual
system. You get no feedback as pressures go up.

The Devcon polyurethane mixtures the Isocyanate component is
dangerous in the unreacted state. Injuries are primarily pulmonary
but there are reports of other effects.


Even steel parts will deform and can break under pressure. 

I had a 1/4" wall steel vessel fracture with just my 20 ton hand
pumped jack before (it was unknown steel, I won’t use scrap again to
make vessels…), it made an impressively scary and pants soiling
“Bang!”, but thankfully no shrapnel. So be very careful with
pressure vessels!

Nicholas Carter and Felice Luftschein

Thank you Jesse Brennan! You are absolutely correct that there are
some serious safety issues with the die forming advice that was
given, both using PVC pipe to contain urethane in the press, which
will shatter, and mixing flexane which is carcinogenic and extremely
toxic. I have personally mixed a lot of flexane, written about it
and taught people to use it, and want to state for the record that it
is not advisable. There are sources for buying urethane now, and
there is no need to expose yourself to toxic chemicals when mixing
it. Urethane is a wonderful material to use in die forming. It is far
superior to rubber. It doesn’t wear out, and is worth the price you
pay for it.

I also wanted to point out another option for hydraulic press frame.
There are plans for a bolted-together press is in my book,
“Hydraulic Die Forming for Jewelers and Metalsmiths,” available on
Amazon. The press consists of drilled steel plates, one-inch threaded
rods, washers, nuts, spacers and springs. The top platten can be
drilled to accept Bonny Doon tools. It is easy to put together and
requires no welding. Steel isn’t cheap, and the drilling should be
done in a machine shop, but it is a safe and reliable design. One
more thing. Messing with a hydraulic jack to add a gauge is also
risky, dangerous and something you shouldn’t attempt. There is a
source for jacks with a gauge in my book.

Susan Kingsley

I scraped the gold paint off our Bonny Doon press hydraulic jack to
expose the label. It was the same Central Hydraulics 20 Ton pump that
Harbor Freight sells (without the gage, trimmed corner and

using automotive style presses will work for using urethane as a
bottom dies.

I worked at a sheet metal company that built plastic and paper
machine for a company.

there engineers would design a product and it was are job to build
tooling and form the parts.

some of the engineers would design out of this world concepts. But
we found that all you need is top punch the shape you want a bottom
die made from urethane rubber the hardness is a trial and error. soft
will get more detail.

Urethane has a characteristic that the more pressure applied the
less it will deform the first 1/8 inch it move then it take 30 time
the force for the next 1/8 and so on but we use it all the time as
its less expensive to only build one die or punch then a die and
punch that mate. the urethane doesn’t have to have much holding in
case meant it need to expanded when the punch push in the urethane
acts like a liquid and deflects out but with a lot of pressure it
will push the metal in punch and take its shape. thin metal shouldn’t
take much pressure I bend 4’ of 1/8 plate with a 15 ton press. Some
time by carving out voids in the rubber assist in the forming or just
cast a bottom die of you top with the devcon. that what its made for
Using a press with air assist it would be wise to put a expanded
metal screen in front and back for a containment for safety. some a
the jacks have a pressure gauge to tell the force. The harbor freight
presses work stock with no modifacations there bolts they use are
soft and will fail with to much pressure Northern tool has some good
presses for a good price

I make a bench model press that just brakes metal but can be changed
to press what ever

Contact me off line for a picture of the press
Thanks Randy
AKA Enjen Joes

Hello Orchidians,

I’ve read a number of postings recently regarding hydraulic forming.
Let’s talk about automotive presses, jacks, urethane, Bonny Doon
presses, and how to make the right choice when making any purchase.

My first press was the front end of my truck. I had a 5 ton jack
that I would stick under the front end axle, sandwich the gold in the
conforming die and place it on top of the jack. When the front end
started to lift I could figure on about 3000 lbs of pressure coming
to bear on the metal. This was right after "The Metalsmith Papers"
was published in 1981 and I was hooked by Mark Paisins article about
hydraulic forming. It was almost ten years later that Lee Marshall
engineered the first hydraulic press for metalsmiths. That press has
gone through several improvements over the years always improving to
become the best press for the metalsmith.

I’ve learned a lot since then, one important lesson was “Don’t try
to re-invent the wheel”. If the right tool for the job is available
it is far better economics to purchase it than to try to build it. If
the right tool for the job is not readily available then you must
determine if it is economically feasible to research, design, and
engineer a new tool.

You should know that I do own an automotive press and Yes, an
automotive press (which is designed to press bearings) can be used
for metalsmithing applications, but it is certainly not as effective
or efficient as a press designed for the sole purpose of
metalsmithing and it’s processes. I use my automotive press for
pressing bearings only, which it does quite well. I came close to a
serious injury once when I tried deep-drawing in the automotive

Ask yourself these questions: “What is my time worth”, “What is my
safety worth”, and “What does my jewelry deserve”? Are you a
professional jeweler, a retiree, a hobbyist? Each will have their
own needs, but whether or not you are a professional jeweler, one
that makes a good living by creating jewelry, or a retiree with
limited time, or a hobbyist with a limited budget, an automotive
press is going to prove itself expensive over time due to it’s
limitations, the extra time involved to setup dies, the lack of
safety, the lack of expected results, and the lack of support.

Also Yes, the ram or jack that Bonny Doon uses is the same one you
can buy from Harbor Freight for less than $40 (without gauge). If you
want to put a gauge on it you’ll need a mill ($) and specialized
tooling to install the gauge, and then you’ll need to learn how to
port the pressure through to the gauge. You might convince a local
machine shop to port the gauge for you. When you are finished you’ll
not only have spent lots of money, but lots of time too, this I can
guarantee! :wink: There are many ways to build your own press but none
of them will save you time or money over the long term. I know this
intimately as I have built and used many “homemade” presses. Again,
ask yourself, how valuable is your time? How important is it for you
to obtain the right results when making your jewelry?

Understand that the new press frame from Bonny Doon is designed for
the sole purpose of metalsmithing, and is built to a much higher
standard than what is required of an automotive unit. All presses
flex and stretch under pressure, some more than others. The
automotive press frame will flex quite a lot when used. Here’s a
test: take a 3" circular blanking die and blank some 18 ga or thicker
metal. The automotive press will usually go off with a very loud bang
as the die shears the metal. This is due to the instant release of
stored energy/force of the stretched frame springing back to rest.

The new MKIII Bonny Doon is designed and built to minimize flexing
thereby minimizing the instant release of stored energy so you can
blank without the annoying “shotgun blast” each time you pop a piece
of metal. The lack of flex also allows for repeated results with more
accuracy when using silhouette dies, conforming dies, non-conforming
dies and coining dies.

At todays silver, gold and platinum prices can you afford to get
less than perfect results each time you form your metal?

Now, let’s talk about urethane! There are numerous formulations of
urethane probably numbering in the thousands. You can purchase
urethane and/or make your own, at quite an expense to you, your
health, your time, and your wallet. The urethane from Bonny Doon is a
formula designed for forming metal under less-than ideal
circumstances, the metalsmiths shop, where small runs in various dies
demand more from the urethane. I’ve seen lots of low quality urethane
fall apart or crumble with little use due to it’s inferior make.
Rubber can also be used in place of urethane, but you will have
troubles trying to repeat your results, you’ll end up with lots of
torn metal and unusable parts. As always, you will get what you pay
for, especially when it comes to urethane.

“Buy once and buy well” is a saying from my mother who grew up
during the depression when people could not afford to waste money. It
was smarter economics then to spend $5 on a pair of long lasting
leather shoes than it was to spend $2 on a pair of short-lived
plastic shoes.

I sincerely hope this guides the prospective press buyer into making
the right choice for their needs. I truly wish for all of you the
time and inspiration to create beautiful and unique jewelry. Avoid
the pitfalls of re-inventing the wheel and wasting your time and
money on inferior tools.

G. Phil Poirier

I scraped the gold paint off our Bonny Doon press hydraulic jack to
expose the label. It was the same Central Hydraulics 20 Ton pump
that Harbor Freight sells (without the gage, trimmed corner and

Yes and no, Lee totally rebuilt those jacks so they would work
properly, the standard Harbor Freight unit is kind of a hit and miss
affair as to how leak free it is and what kind of junk is left
inside the jack body to cause you grief later on.

James Binnion
James Binnion Metal Arts


I make a bench model press that just brakes metal but can be
changed to press what ever 

I would appreciate seeing a picture of your set up please.

Thank you Ed Katz