The seal on the ram isn’t a pressure seal, just a dust/dirt
seal. Small dings on the ram could eventually allow enough dirt
inside so that the cylinder wall could be damaged, or come in
contact with the pressure seals on the piston and damage them.
Using one of these bottle jacks inside, in a shop, doesn’t
expose it to much dirt though, and they last for years being used
and abused in mud and dirt. I don’t think I’d buy a new jack
with the dings though, I’d rather buy it ding free and have the
chance to ding it up for myself. Just my 2 cents. Rick B.
The seal on the ram isn’t a pressure seal, just a dust/dirt
Anyone out there have experience or knowledge refilling 20 ton
bottle jacks? Since I’ve been reading these posts I’ve dusted
mine off got ready to use it and the ram dosen’t drop down after
use, even with weitht on it. I can really forse it down with all
my weight. Is it possible air got into the jack? appreciate any
help, thanks, Don Wollwage
Most jacks I’ve seen have a fill plug on the side, sometimes it
is a rubber plug sometimes a screw. You lay the jack on the side
and make the fill point the higest spot. Use a small funnel
(never again to be used for food)or a piece of wire (14 gauge
platinum should work ; )) to trickle the fluid in. You can buy
hydraulic press fluid at some auto supply places, in a pinch
brake fluid will work but try to find the right stuff.
It could be the release valve is clogged too - is the jack
springy when you push down on it? That usually indicates air
(which compresses), if it is not springy then it could be the
valve is clogged and needs to be taken apart and cleaned.
Sometimes the ram will stick a bit too, usually a few up down
cycles fixes that (got a car handy?).
Also on another tangent - has anyone ever experimented with
hydrostatic and explosive forming (not nearly as dramatic as it
sounds)? We did a bit of work in these areas in tech school
(manufacturing not jewellery but the ideas are the same) if
anyone is interested. Tends to form metal without introducing
stresses associated with die forming.
Island Gem and Rock
“For those of you that use a hydrolic press do you use mircarta to
cut your pattern from…Is there something out there that is
sufficent that is eaiser to cut?”
I held off responding to this because of my limited "hydraulic"
experience. Many offered the suggestion of Plexiglas sheets and
mentioned the brittleness. I attended a hydraulic press workshop and
was told to avoid the Plexiglass and to use acrylic sheet instead
because it doesn’t have the tendency to break. Of course leave good
margins of support around the die boarders.
For anyone lucky enough to live near a plastics supplier, many have
cut off “scrap” bins where material is sold, at a great discount, by
Orchid Rules!..Karla in So. California
Many offered the suggestion of Plexiglas sheets (... for dies...) and mentioned the brittleness. I attended a hydraulic press workshop and was told to avoid the Plexiglass and to use acrylic sheet instead
G’day; I may be wrong but I have been given to understand that your
’Plexiglas’ is the same animal as our ‘Perspex’ and that is indeed an
acrylic resin. Perhaps Polycarbonate would be a better plastic? That
is the transparent stuff used in police riot shields. Then there is
another one - opaque- called ABS resin which is used for making small
gears and other parts needing hard toughness. Ask around. Cheers,
– John Burgess; @John_Burgess2 of Mapua Nelson NZ
I am forwarding this mesage from Lee Marshal who makes the Bonny Doon
Press as it covers some aspects of the RDevices press
A Bonny Doon Press for $325 ? Not likely folks��
Recently, there has been a thread on Orchid about a press “similar to
the Bonny Doon” that is being made in Southern California that costs
I went to the site where the press in question was shown and
took a pretty close look at it. Here is the site if you want to take a
After a pretty careful perusal, here is what I came away with:
Why is it always the case when somebody copies an existing design, they
always leave something out? I think that it is because they are too lazy
to put together their own unique design, and as a consequence does not
take responsibility. This is certainly true of the “knockoffs” that
occur in jewelry. Each and every one of you is undoubtedly able to
relate similar experiences that you have had to deal with.
What has happened in the building of the press shown is that a critical
part was left off, making the press almost worthless when pushed to its
maximum limit. The copier simply doesn’t understand the design concept
that I used when I created the Bonny Doon press. Each element that goes
into the building of the press frame is important, and cannot be
ignored. I have said it before, and I say it again: "Every thousandth of
an inch of energy that goes into frame flex is energy that is not going
into the metal that you are trying to work.
The failure of the copier to recognize that the strength of the press
frame was severely compromised by their casual elimination of the
critical part causes me to doubt their overall comprehension of the
forces involved, as well as their skill and ability in fabrication.
Parts breaking off of a press frame while under stress is not a pretty
When I was developing my press, I was concerned about this sort of
thing, and placed a 50-ton ram in a frame to do a stress test. At 50
tons, the top and bottom horizontals had achieved a permanent “bow”, but
nothing broke. I doubt that the same could be said about the copy.
The choice of platen size (10" x 10") as a standard (once again) shows
a lack of understanding as to the forces involved. There is no way that
a 20-ton jack can fully utilize the size of these platens. A 20-ton jack
simply doesn’t have enough force to effectively spread itself over so
much surface area without additional support. Under sustained use, the
platens will start to look like “potato chips”. Also, since the uprights
are further apart, there is additional “bowing” occurring in the top and
bottom horizontals. There is no additional reinforcement in this
critical area unlike the Bonny Doon 6" x 12".
Because there is nothing to stop somebody from copying my design, and
because I didn’t want to have to defend myself in court if somebody got
hurt using a press that “looked like a Bonny Doon”, I have placed a
serial number on every frame that I have made. It is stamped into the
metal of the upper platen. This way, I can sleep at night.
JACK WITH GAUGE
The copier has chosen to drill and tap the jack base on the side
opposite the pump (unlike the Bonny Doon). While there is nothing
inherently wrong with this, I was puzzled why he didn’t copy the gauge
location as well, as the cost of the fittings, tubing, and additional
assembly time is obviously more expensive. What occurred to me was that
the reason it was placed on the side opposite the pump was so that the
jack could be drilled and tapped without taking it apart. There would be
no chance of messing up the complicated area around the pump and one-way
valves directly in harm’s way if you tried to machine the jack as I do.
Since I take the jack apart as part of the machining process, and use
all new seals upon re-assembly, I do not have to worry about metal chips
damaging the works. His method saves time, but at what cost to the
Because I take the jacks apart and do a complete rebuild on them before
putting them in stock, I give a one-year warranty on the hydraulics, and
a lifetime warranty on the frame. I have never had a frame failure of
any sort. I have had some jacks fail in less than one year, and I have
always replaced them immediately. I have no idea of what kind of
warranty the copier is offering (if any). I have tried to contact him,
both directly, and through intermediaries, and have not received any
reply, either by phone or email.
The usual service life of the jack that I use is 3 to 5 years. At that
time, it is simply returned to me and I rebuild it and return it to you,
issuing once again the one-year warranty. I give one-day turnaround on
repairs. When you start using the press in your work, it becomes a major
companion and partner. I regard getting you up and running again more
important that a new sale. Repairs take precedent at Bonny Doon!
One of the other posters to the Orchid thread was asking if the copier
was also going to offer tooling. Without any communication from the
individual, there is no way to tell. It is not apparent from the image
on the website if the platen is drilled for tooling holes or if they are
there, if they are compatible with the standard that I established when
I developed the tooling for the press. Just in passing, every piece of
tooling that is available for the press was designed by me. As far as I
know, nobody else has chosen to make tooling for the press. This is one
area where there is a wide-open field, but nobody has chosen to open the
While it is never easy to look at someone else’s operation and determine
production costs, here are some observations:
The choice of platen size is a dead give-away that the cost of packaging
and shipping was not considered. The frame cannot be placed in a
cardboard carton, but must have a wooden crate built. Since the platens
are so much larger than the frame itself, they would simply destroy any
carton. Since I build a wooden shipping crate for the jacks that I ship,
I am quite familiar with the cost of making boxes, and I can tell you
that they aren’t cheap.
With the gauge mounted as it is, and it’s fragile tubing stalk, what
shipping method would be used for it? Would it be removed, the opening
plugged, and the purchaser have to re-install it? Or, would another
wooden box be required?
UPS will ship packages weighing up to 150# (although they will moan a
lot, and sometimes take out their vengeance on the offending package.
With the 10" sq. platens weighing 58# just by themselves (the weight of
the entire 20 ton BD press frame), the shipping costs are going to be
pretty substantial for this sucker.
There will always be those for whom the apparent cost is of tantamount
importance. For those folks, this “knockoff” may be what you purchase.
May I suggest that you look beyond the price and look instead at the
costs that don’t show?
Several years ago, I had the good fortune of touring the Kohler factory
in Wisconsin. They make all kinds of ceramic fixtures, and have an
"Artist in Residence" program where clay people go to heaven. What ever
you want in the way of clay is available to you at no charge, and is
delivered to you by forklift! While there, I went through their
showroom, which included an historical section. I noticed a motto that
had been penned by one of the founders:
“The best articles are the cheapest in the long run. We made it a rule
not to see how cheap we can make it, but how good we can make it for a
James Binnion Metal Arts
4701 San Leandro St #18
Oakland, CA 94601
End of forwarded message
I am forwarding this message from Lee Marshal who makes the Bonny Doon Press as it covers some aspects of the RDevices press
I am forwarding these thoughts, culled from Confucius, as they cover
some aspects Lee’s message:
“Clever talk and a domineering manner have little to do with being
“He who engages solely in self-interested actions will make himself
…I don’t know who makes the best press, whether it is Marshall or
Harbor Freight or R&D Evices or any one of the many other firms who
produce presses - but I do think it is not seemly to bash the
competition. One of the things that I treasure about Orchid is that
we are all in the same business, and we all manage to play together
Thanks for listening -
I don’t think That Lee Marshall was “bashing the competion”… what
he was doing is giving a very good explanation of the time and
efforts he put in to make sure that his press ( Boony Doon) is
designed to last and be the best for the particular applications
that it is design for. Being an Engineer, I could understand exactly
what he was talking about… I used to design and built 3 post
Vulcanizing presses using a hydrolic System for making large rubber
molds and our presses had many features that were better than our
competions.The best way to sell them was to explain all the
differences and the engineering that went into the product. Using
larger plattens does create a problem unless the metal is
sufficiently thick enough to eliminate any warping of the press
plattens while the press is under pressure.This is more critical in a
stamping press than aVulcanizer as the large mold frames used in a
vulcanizer use 90% of the platten diameter… If a large platten is
used on a hydrolic jack, the thickness of the platten has to go up to
reduce the posibility of warpage.If the tools are not properly
aligned in such a press, damage will occur to the plattens as well as
to the jack. Using thicker plattens will dramatically increase the
shipping weight of the press so I do believe he was giving some very
good arguments for being very careful with the selection process of
the type of press to buy. I do not own a press at this time and have
no affiliation with any press manufacturers but I would certainly
follow Lee Marshalls advice in choosing a press if I were to buy
one.Some presses are better designed than others. Merry Christmas to
all on the Orchid List. Daniel Grandi http://www.racecarjewelry.com We
do casting and finishing for jewelers, designers and people in the
trade in gold, silver, bronze/brass and pewter. –
There are priorities to consider.
1 Safety of use and operation
2 A " forgiving " design - Does the design allow small occasional
mistakes without damage to machine
or product. Is the machine easy to use.
3 Initial, as well as long term economy of use
4 Provisions for upgrades and modifications in production design
as well as production volume.
5 Warranty as well as Techinical support .
Lee Marshal’s statments about the qualities of his " Bonny Doon "
forming press show an attention to quality issues . I would look at
this item first before I considered an alternative.
As I am returning to school to learn another skilled trade ( 2 year
school at Paris Tx. ) I will not need one at this time. I will
however, keep this product in mind . My qualifications, Journeyman
Millwright / Maintaince Mechanic with 28 yrs exp.
ROBB - Retired Old Baby Boomer
Again, Thank You all for the support as well as the which
this group has provided over the Years.
With all due respect, I think we’re forgetting something here. A
hydraulic press is a tool, like your bench vise. In fact they have
the same function–compression. I’ve even used the vise to do the
exact same job at times (die forming) when a press was unavailable to
me–with my (laughable) muscles replacing the power of the
bottlejack. We’re not evaluating the steam engine or the cotton gin.
Reapply your considerations to your bench-vise and see how they
Gary Strickland, GJG
The Bonny Doon web site is www.bonnydoonengineering.com
Check out the gallery and Discussion Group, where one can ask
questions, as well as see, read, and share interesting postings
related to the hydraulic press.
The catalog is available, as well as educational articles and