Beltline moldings

[TheRodDoc]

000 00000 00000 000 000

[bobadame]

Maybe try a hard urethane insert made to fit inside the channel. Then press it between a male and female die made from hard wood well greased. Or make these dies to fit a Hossfeld if you have access to one.

[anders nørgaard]

Looks like a tuff one to make Richard :o

What kind of material are you using?

What is a Hossfeld????

[Boogiemanz1]

Richard, you may have to try cutting away most of the lips in the area to be contoured. I assume that the lips are basicly there to retain clips, so if you need a clip in the contour area you may have to tig it in to the edges. With most of the lip gone you should be able to make some wooden or aluminum dies to press the contours, or you may be able to do it on a pullmax with male/female dies.............john

[Tisdelski]

hi richard,
it looks like a corner on a curtain rod. i wonder how the factory does it ?

[anders nørgaard]

hi richard,
it looks like a corner on a curtain rod. i wonder how the factory does it ?

Gary,
A 2" tall curtain rod would be able to holda HEAVY curtain :lol: :lol: :lol:

BUT: You're right http://www.metalmeet.com/forum/images/icons/icon12.gif

[Randy Ferguson]

Hi Richard, Dan Shady has just the stuff that may work. I don't recall the name of it, but it puts me in mind of kirksite, except it will melt at the boiling temp of water, if I reacall correctly. I need to call Dan tomorrow, so if I can remember, I'll ask what it is and where to get it. I think you could make dies from that stuff and melt it away in boiling water. It's the only solution I can think of that wouldn't be a real pain. You've done tried all those anyway, apparently!!!

[Boogiemanz1]

Gary, I imagine the factory uses a series of rollers and mandrels to build them...................john

[danlshady]

Cerro Bend, Mcmaster Carr. You say a 90 degree bend, I assume 90 degrees like tour pictour or are you meaning a true sharp 90 degree?
Dan

[Doug98105]

The stuff Randy mentioned is Cerrobend, a low melting point bismuth alloy. The various bismuth alloys melt at 160 F+/-. Costs about $25/pound. Pictured is one ingot I have marked 158 meaning the melting point. Until you pick it up you might think it's an aluminum casting. This one is just shy of 4 pounds.

Melt it in a double boiler on the stove, fill the inside of the molding and bend as if it was a solid bar. Then melt the Cerrobend out.

http://www.metalmeet.com/photopost/data/500/Cerrobend.jpg

Doug

[anders nørgaard]

Doug,

Looks like that would do the trick http://www.metalmeet.com/forum/images/icons/icon14.gif Thanks for sharing http://www.metalmeet.com/forum/images/icons/icon7.gif

Is the Cerro Bend reusable?

[Doug98105]

Yes, it is reusable. If it wasn't some of us would be broke real quick since it always seems to take more than you'd think to fill the bending area.

Doug

[anders nørgaard]

Yes, it is reusable. If it wasn't some of us would be broke real quick since it always seems to take more than you'd think to fill the bending area.

Doug

Thanks Doug! Yes, it looks pretty expensive :o

That would be the way I'd try doing it! Maybe find a cylinder having the mold corner ID (or turn one from wood) Make an out side wooden die and bend the mold like in a tube bender.

One other question:
Does the CB "stick" to the "mother material" or does it just form inside?
Thanks again!

[Doug98105]

Here's a little experiment with Cerrobend.

On the left is a scrap piece of ornamental turning in delrin plastic.

In the center is a metal candy container with one pound of Cerrobend which I melted with a hand held heat gun. When it goes liquid it's like molten lead except not as hot. In the lower left corner of the Cerrobend you can see a spot I touched with my finger tip to see if it was liquid.

Once it was liquid the plastic piece was pushed down into it. After a few minutes the Cerrobend hardened and the plastic came right out. The plastic has sharp details which didn't pick up well in the cerrobend. (there are some other low temperature bismuth alloys that may be better at capturing fine detail).

On the right is some light gage copper pressed into the Cerrobend "die" with a urethane pad. You can see not much of the sharp detail of the plastic transferred to the copper.

http://www.metalmeet.com/photopost/data/500/cerrobend2.jpg

Doug

[edwardd_]

Richard,

Don't recall how many you need to make. Is it possible to make the bend from solid and weld / braze the straight pieces to the bent corner?

Might be quicker and easier for just a few.

[Ron Naida]

Richard,

Cerro put out about a half inch thick manual years ago. It had a blue cover and inside were instructions on how to use all their alloys including casting intricate model railroad parts. They are located near Pittsburg, Pa. give them a call.
Ron Naida

http://www.cerrometal.com/rod.html

[Ron Naida]

Cerro instruction manual. I have had this one about 15 to 20 years. One would think they would still offer at least a reprint or copy.

Ron Naida


http://www.metalmeet.com/photopost/data/3230/medium/Cerro.JPG

[bobadame]

Cerrobend would do just fine. I think a urethane fill strip would also work. You would have to grease it up so you could pull it out after you've formed the piece. The urethane should be in short segments sort of like the "rat" in a mandrel bender.

[CCWKen]

I think Bobadame is right. A PE strip could be notched in segments with the form of your molding. The notching will make it easier to pull out. You'll need to keep one end captive so the outer radius can be stretched. Use a die bender. I don't think bending it over a pipe/form will give you good results.

Me, I don't have access to a die bender so I'd roll form it on the bead roller with custom dies and leave the legs straight out. A few "rolling" passes should get it curl. After the 90 is in, then I'd turn the closure with a PE insert. Start the closure manually then roll it between your form roller and a flat roll. What little wrinkle you get on the closure tab will be on the back side.

I've made radius T-strips with the bead roller using a guide I saw somewhere. I can't remember if it was here or the other site. Basically, the guide forces the outbound side down and bends the radius. Adjust it down with each pass. With your's being just an open form, the dies can be made to E-Wheel (stretch) the form. The guide will just hasten the bend.

[CCWKen]

Your first pass dies would look something like this. The clearance at the bottom of the form should be tighter than the sides to roll (wheel) the form. The slots in the opposite die will keep the legs from buckling and provide some capture or shrink. The slots should be just a few thousandths over your material thickness.

Once you have this form made, you could also just shrink the tabs to get your radius. Then form the capture lip as above.

http://img.photobucket.com/albums/0903/CCWKen/Tools/Bead%20Roller/RollDies-Pass-1.jpg

Forgot to mention, the die set in the picture is actually upside down. :eek: Feed your stock in as the form of a channel.

[anders nørgaard]

Hi All,

I also thought of PE dies..... but in another shape. A die that fit the inside of the molding, split into 3 strips. When the molding has been bent, pull out the center strip and next, the 2 side strips

http://www.metalmeet.com/photopost/data/500/medium/Body_Molding_Line_Tool.jpg

[dude]

Is there any reason that a brass molding couldnt be used instead? saves you having to form anything ,and alot easier to bend to the curve you need

.....jason

[bobadame]

Urethane is a wonderful thing. We used to use it as a wear pad in an operation to deep draw 20 gage stainless steel sheet into canteen cups for the military. These were formed in one shot against a thick rubber bladder which was pressureized to around 15,000 psi. I don't remember the durometer but it was hard plastic about equal to common Delrin.

A plastic filler strip would be reusable many times. A metal strip will soon work harden and break. The point is that the filler material needs to shaped exactly like the inside of the trim. This will require some care and time. Also the bending dies need to be carefully made. Might be best to not have to keep making the tooling.

[wtowns01]

If you want the plastic that melts try this:

http://www.wfr-aquaplast.com/tmppcc_default.htm

It is very easy to work with and gets quite hard.

[Dema]

Hi,
I'm looking for a Cerro dealer in Europe, somebody known if give one or can supply the contact address of cerro in the U.S. ? :confused:
Thanks,
Dema

[edwardd_]

Dema


Here is the Cerro site http://www.cerrometal.com/index.html

I did not see any sales persons other than US. But, they have email and might be able to help you.

HTH,

[Cal Davis]

I have seen this done before with molding that were deeper and much more narrow. If you will pour the molding full of lead, bend it to the radius that you want, then melt the lead back out you should have a perfect radius.
Let me know if this works,
Cal

[Dema]

Dema


Here is the Cerro site http://www.cerrometal.com/index.html

I did not see any sales persons other than US. But, they have email and might be able to help you.

HTH,

Many thanks for your help Edward :)

[Boogiemanz1]

I have used the lead process to straighten and repair mouldings, but never to bend them......I'd be interested to see it work.............john

[llewellyn]

I don,t know if this is to late , but here is an idea. If you think of making a hammer form for the corner out of scrap metal & make it in 3 layers, with the center layer thick enough so that when it is removed the outer layers can drop out of the folded edge. I would make the center layer out of a piece of 3/8 ths thick metal. Then the top & bottom layers out of 1/4, with a piece of flat bar welded on edge to each of them bolt these together & shape as required .Anyway as i said just an idea
later llewellyn

[firstgenbird]

You could lay a stack of 2" wide, 10 mil thick shims inside the shape to support the edge while you bend it over an MDF form. You could even make them of various widths to match the inside of your shape. The shims would slip enough to take the shape, much like making an arch is done in woodworking. Slice the shim lengthwise from the back side to remove it. Once the first shim is cut out, the rest would be easy to remove. I'm thinking fiberglass/epoxy PC board material would work for this. You might find some other suitable materials shopping a local plastics supplier drop bins.

[LARGELY]

Hi guys,
The stuff Randy refered to is called Cerrobend. It sounds like exactly what you need. Try www.Hitechalloys.com
Hope this helps.

Larry (Largely)