Nicholas B's build of the Tiger I initial here:

https://armorama.kitmaker.net/forums/122271&page=1

got me to wondering about round PE brass and how to bend it. The exhaust stacks on his model came pre-formed:



But the ones on the Voyager upgrade for my Tamiya Early Tiger I are flat and need to be formed. I've held off finishing the kit because I'm daunted by the task.

Suggestions?

Well Mission Models had a set of brass tubes that was made for this purpose.

Best thing is anneal first then take a brass tube and roll until you have them round.

My opinion.

Ola Bill

The trick to doing these kind of things is first heat up the PE part so it becomes a bit more flexible and take a cilinder of a bit lesser diameter then the piece should end up with.. Pu the PE part flat on your cutting mat and roll over it with the cilinder. You will find out that the PE part bends nicely in a round shape all by itself

there is also another device by The smallshop EU



which allows you to bend the shape gradually using different sized tubes, quite a usefull tool in my eyes

HTH

Keith Forsyth

And a closer look at this tool, right here on our network as well!

In a previous lifetime I worked with metals for a living, and have to agree with all the tips above, Bill....making a radical bend in brass (or any other light gauge metal) as the stacks that are shown in your image would most definitely benefit from the annealing process, for a more smoother, fluid cylinder, and depending on the gauge of material that you are trying to form, you may actually have to use a miniature roll (Micro-Mark used to sell a fine machine) to achieve the proper cylinder form...

Great idea! But HOW much to heat it? And with what? A lighter? A paint remover gun? A soldering iron???

Don't want to inadvertently melt the sucker....

If you use a barbaque lighter .....(I use this) and a pair of tweezers to hold the piece......wait until it becomes red-hot(dont worry---it wont melt,this was my fear at first also)...then dip it in water ......presto.....VERY bendable brass!(try it on a scrap piece of brass fret if youre nervouse)

Annealing Brass:

Heat with a candle or lighter until you can see the colour of the metal change. In bright light you may not see the "red" of red hot, but as the brassy colour starts to go blue or greenish, you're in the right ballpark. You don't need to quench brass this thin in water, it will quench in air in no time. Saves a step.

Forming brass radii:

While the Small Shop press looks OK, the best thing I've found for getting literally any bend radius is to use a stack of medium stiff rubber and a rod of smaller diameter than the diameter you want to end up with. Gently press the anealed sheet into the rubber with the dowel/rod. Roll it back & forth to work the part into the rubber. The harder you press and the more you roll, the tighter the radius. You can use a rod much smaller than the radius you want to end up with and still get really smooth bends by not pressing in so hard and by making sure you roll over a larger area. Practice, of course, is the key, but it's not hard to do right off the bat.

This process works especially well woth perforated PE like cooling jackets & "perf plate" as the brass almost never forms those annoying facets that mean you didn't get a smooth bend.

The trick with the rubber is for it to be not too soft & not too hard. 4 or 5 layers of bicycle innertube are good as are white drafting erasers. The larger, yellow, gum-type art erasers are generally too soft. Car tire rubber is too hard.

HTH

Paul