I’d like to bend some Plastruct guardrail to fit around a crossing signal like the picture. Most attempts have ended up in multi-piece disasters. Slight curves work okay but not the fairly tight U shape I’m looking for. Any tips would be appreciated.
Thanks
Ricky
Not sure if you tried heating up a piece of it. I can’t think of another way unless you have 3 pieces. 2 represent the sides and the third is cut down and bent using heat or althernative method - it would look something like this:
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/ \
Try using a heat source, i.e candle or hot water. Heat and gently bend, might take a little time.
Terry
i used a 1971 lincoln and a few bottles of budweiser.
grizlump
[(-D] Bet that did the job in a hurry Grizlump! Rickey, in the real world, stuff like that is formed in what’s called “conformal dies”. Two grippers clamp the end of the rail and pull it around a male die that’s got your curve in it. The combination of high pulling forces and the shape of the die, like the inner profile of the guardrail, prevent it’s kinking. In HO scale (I’m using it as a default here, adjust if you model another scale) it looks like the prototype has about a 5 foot radius curve so that’s about 11/16", Get a dowel a little bigger than that (3/4") and find a way to spin it, or clamp it in a vise and file it to the basic diameter you need. Then file and sandpaper so the dowel snuggles down in the inside of your guardrail. You’re basically reproducing the inner profile of the guardrail on your dowel. It’s going to look like a barrel with the curves of the guardrail in it. Once you have that take a length of your plastic guardrail, let it sit in a pot of boiling water for a few minutes and then using heavy gloves wrap the softened plastic around your home made “die”.
Lou
I thought a grumpy German would be drinking something a little more European! That was too funny for one of the first post I read this morning.
All, thanks for the suggestions, I will let you know how it turns out. Hopefully with all the need for heat, I won’t find myself in the ER! But then again, its -23 F here in Omaha and maybe a little heat will feel good!
Ricky
P.S. grizlump, know where I can find an HO sacle 1971 Lincoln, I can get the Budweiser with no problem!
A lamp light bulb held close to plastic should work like it does when laying vinyl floor tiles down for a sloping drain. The bulb’s heating must be monitored closely before it goes from pliable to melting point.
At the bargain table at a chain craft store, my wife had bought a heat gun intended for use by rubber stamp hobbyists and scrapbook hobbyists for embossing purposes. It turned out it did not work for her application so she offered it to me. As it happens Woodland Scenics new vinyl grass sheet also uses a similar heat gun (sort of like a hair dryer but with much more heat output) and I had bought a few sheets to experiment with (by the way, if you use WS’s plastic foam as the base I do not advise using the heat gun vinyl grass application over it) so I had a hobby purpose for it. They are called crafters heat guns or embossing heat guns.
I have since used it to bend plastic castings much like you want to. I have to think it is safer than an open flame candle and more practical than holding plastic over a soldering iron tip. The heat is high enough and comes out in a concentrated blast of air so that you do not have to wait long before the plastic softens. The trick (apart from not burning your fingers in the process, or totally melting and ruining the piece!) is to know when the softening process is just right so you can quickly dowse the part in a cup of cold water to re-harden it. You only get so many chances to re-do or un-do before the plastic is basically ruined, but with practice you can almost sense when the softening point has been reached.
It does release plastic fumes so don’t do this in a tightly confined space or for long periods of time.
Practice on left over plastic sprues. Following the late kitbash master Art Curren’s advise I keep all sprues so I have a nice supply to practice on.
If you have young kids in the house I advise putting the heat gun tool away after each use. It looks too much like a hair dryer and might be tempting.
Dave Nelson
Lou, I used your method, boiled the plastic, then wrapped it around a plastic soda bottle lid. Boiled it a little more with it rubber banded inplace, then wrapped it around a marker to get the final diameter, same thing, boiled it with it rubber banded, came out great. Even has a little twist on one end so it looks like a 71 Lincoln hit it!
I amy try to post a pic next week when I get the right camera to do so.
Ricky
Ricky,
Glad to hear the technique worked so well for you. We all look forward to your pics.
Lou
Here’s the picture. As you can see one end is twisted but i can live with that, at least i have the technique down now.
Ricky