Hydroforming

[Friartuck]

Has anyone ever done Hydroforming in a home brew fashion? If so, what was used as the chamber (enclosure)? Looking to make a sheet metal cover that was probably stamped. The female die is fairly easy to make using Plaster of Paris which should pick up the ridge detail of this part. The wide throat on the left should be easy. There is a high ridge on the right that needs to be captured. Cover is .040 thick brass.

Edited June 5, 2016 by Friartuck
photo added (see edit history)

[Restorer32]

I'm thinking you would need 2 substantial slabs of steel or aluminum. One hollowed out to hold your pattern (maybe wood) and the other tapped for a fitting to attach to whatever source of pressure you choose. I'm thinking a hand operated hydraulic pump? Bolt the two slabs together with a gasket and your material of choice and start pumping. Be sure to allow a way for air to escape from beneath your material as it forms around your pattern. Better but more time consuming would be to machine the pattern directly into the base plate. A negative base plate could also be cast and machined flat. Interesting.

[Gary_Ash]

I made a rosette trim piece as a crank hole surround on a grille shell.  I turned the female die from a ~4" diameter aluminum bar with a couple of semicircular rings.  A piece of heavy steel pipe with about 3.5" i.d. was placed on top of the die as a retainer, a 0.020" thick brass sheet was placed on the die surface, then a 3/4'-1" thick urethane pad was loaded on top, followed by a thick section of steel bar as a plunger that was a sliding fit in the steel pipe.  The assembly got placed in my 12-ton Harbor Freight press and squeezed.  It worked sort of OK, but I got better shape definition when I took the assembly to the 30-ton press at work.  I did try several durometer ratings of urethane in the 40-100 durometer range.  The softer stuff works well for getting the basic shape but harder stuff is needed for fine details.  Under pressure, the urethane behaves like hydraulic fluid.  The tight fit between the steel bar plunger and pipe is needed to keep the urethane from squeezing through the cracks.

 

You didn't say how large your piece is or how thick the metal needs to be.  That will determine the press tonnage you need. I don't think a plaster of paris die is going to be strong enough to stand up to the forces.  There are some epoxy-steel powder mixtures, e.g. Plastic Steel or Lab Metal, that would be strong enough.  Use carnuba wax on your original part as a parting compound before casting the Plastic Steel die. 

 

Otherwise, you might be better off investment casting some replicas if you can have the part be thicker, perhaps .090"-.125" thick.  A good casting house like www.browncasting.com can tell you what minimum wall thickness they can produce.  You can melt some paraffin wax and paint it on the back side to build up the thickness.  The casting house will then make a silicone rubber female mold and from that make all of the male wax replicas for the casting process.  

[Mark Shaw]

Might be easier to weld two formed pieces together.   Check this out...  http://eaavideo.org/video.aspx?v=1277219627001

 

 

[Rusty_OToole]

I saw a video of a guy hydro forming a jet engine using his neighbor's pressure washer. It can also be done using a hand hydraulic pump like a Porta Power. You tube must have some videos.

 

[Dandy Dave]

HydroForming.  That is using high pressure of a fluid to form a part. That is high Tech for most of us here that are still using and anvil, Forge, and hammers to make a part. With that said there are ways to make a copy today with the 3D printers we have and even a reverse of the part for the other side of a vehicle if you have the buck$ to have it done. All is possible. Dandy Dave! 

Edited May 27, 2016 by Dandy Dave (see edit history)

[Akstraw]

This is an interesting approach.  Please let us know how it works out!

[Guest Roj]

On ‎5‎/‎26‎/‎2016 at 9:09 AM, Friartuck said:

Has anyone ever done Hydroforming in a home brew fashion? If so, what was used as the chamber (enclosure)? Looking to make a sheet metal cover that was probably stamped. The female die is fairly easy to make using Plaster of Paris which should pick up the ridge detail of this part. The wide throat on the left should be easy. There is a high ridge on the right that needs to be captured.

I have done Hydroforming of many frames and what you do is make the bottom of the die and then use a large bladder with hot oil encased when forming the part with pressure.  The part you show above can be made many ways, it can be 3D printed in 17-4 steel, machined in a 5 or 7 axis machining center, formed in a regular die with Kersite to keep the cost down, or hydroforming can also be and option.  If you want the part made give me a yell, and I'll help you through it.

 

Cost

 

3D Printing  approximately $500-800 after it has been sintered

5-7 axis machining   Would have to study the part further, but in the same range

Kersite die  600-1000 but would be able to make about 500 pieces

Hydroforming  Have to study the part further.

[Restorer32]

Could the 3-D printed parts be polished and chrome plated?

[Guest Roj]

To answer the question they can be polished and they can be chromed, I have a 3D printer and I have made and chromed parts in the past.  You will need to 3d scan your part, then upload the print into the 3d printer, It is easiest to make it out of 17-4, then polish it, add copper, then chrome.

[Spinneyhill]

The auto industry is good at chroming plastic. Could a printed plastic part be chromed that way?

[Gary_Ash]

Most shiny metal stuff on plastic these days is deposited by vacuum deposition processes, including evaporation or sputtering.  Chrome and chrome/aluminum alloys are mostly sputtered.  This includes plastic parts of many polymer types and metal parts, even complete car wheels.  Electroplating is not environmentally friendly, so the automotive companies avoid it.  I have been involved in the design and fabrication of systems to sputter chrome alloys on 250,000-500,000 wheels per year.  There is also some spray on stuff that is basically silver (like the old mirror silvering process) with a basecoat and clear topcoat, but I can't imagine it lasting more than a few years.  Most of the shiny plastic knobs on cars in the 1950s-1970s were evaporated aluminum with a clear over overcoat. So, plastic parts can be coated.

 

However, for Friartuck's part, I still want to know how big it is.  Can we have a top and side view with a scale in the photos? If a die was made from poured metal-epoxy or even carved out of an oak block, one could almost hand-hammer the parts into the female mold.  Think about copper bowls and trays that we all have seen over the years.  Sometimes, too much technology is an expensive curse.

[Guest Roj]

14 hours ago, Spinneyhill said:

The auto industry is good at chroming plastic. Could a printed plastic part be chromed that way?

Yes,  The top piece is a plastic part made from a 3D printer and then chromed.

[Restorer32]

I believe the part in question is an ignition wire cover. Plastic might not be heat resistant enough to work in this application. If we had to make one we would carve out a hardwood pattern and hand hammer brass to shape but not very efficient if one wants to make the item available for sale.

[Guest Roj]

On ‎5‎/‎26‎/‎2016 at 9:09 AM, Friartuck said:

Has anyone ever done Hydroforming in a home brew fashion? If so, what was used as the chamber (enclosure)? Looking to make a sheet metal cover that was probably stamped. The female die is fairly easy to make using Plaster of Paris which should pick up the ridge detail of this part. The wide throat on the left should be easy. There is a high ridge on the right that needs to be captured.

If you want it made, PM me, I can and have made parts like this before, if not, that's fine.