Have any of you kitbashers or DIYers used a heat gun to bend sheet styrene? I am thinking of getting an inexpensive HF one ($9- on sale!) with a set of extra focus nozzles (another $7) for use in making custom shapes for car bodies and structures. Any feedback would be appreciated.
Cedarwoodron
there was a talk at an NMRA meet on using 4x8’ sheets for backgrounds but it wasn’t clear where to buy such large sheets until someone said they were used in vacuum forming large shapes.
with a little heat, it may be more maliable than you expect.
They are useful, I have used them for putting bends in rod styrene for large pipes like in the Reading N-1 steam pipes.
Styrene can over heat and expand in the process making it look kind of foamy. So if doing minor bends appy heat in small waves and get a feel for how easily the styrene will want to bend. If the heat gun as a temprature dial that is a plus. Also having something to ben over around the radius you want makes the bend more uniform.
When using heat to bend styrene it helps to have a cold water bath or spritz handy to stop the bending/distortion immediately. To me a heat gun such as is used to strip paint would be a bit too imprecise due to the very high heat and wide dispersion of the heat. I use a much smaller/weaker heat gun used, I think, by the stamping hobbyist crowd. It resembled a small hair dryer, but the heat was more than a hair dryer produces. I have also used a small soldering iron to bend styrene for use as gutter downspouts. In both cases I learned that once the styrene reaches the “right” heat it tends to quickly go too far and distort, hence the useful cold water bath method.
Dave Nelson
I find it too hard to control the heat warpage. If I want…say a .010 curved wall…I just laminate 2 pieces of 0.005 together. Once glued, the curve is permanent and strong.
To capture the look of Miami and the curved walls that several structures have, I used a spagetti sauce pan filled with water and brought it up to near boiling temperature slowly. I immersed the sidewall in the hot water for a few minutes and then brought it out and taped it the side of a one gallon paint can and let it cool. After cooling I removed the sheet plastic and glued it into place to the bottom floor of the structure which had the same curvature as the paint can.
[URL=http://s136.photobucket.com/user/ROADMAN_2006/media/railroadlayout015.jpg.html]
THAT looks great!
For bending styrene rod I just use the liquid cement. Need that for gutters and such.
I use the two stage heat gun that originally was intended to shrink tubing that protects wiring under the layout. Last project was making right angle pipe fittings out of 1/4" styrene tubing. Crucial steps from that educational excersize included finding the right heighth above the gun to allow the tubing to absorb heat slowly. Better to make a partial bend, cool and bend again than to go the full 90 in one push. Additionally, while the bend is slowly approaching the desired angle, do not rotate the tube or it will develope an unwanted twisted appearance. Evidently, I learned slowly, because finding the wrong techniques used up all but the last tube in the package to make four fittings…sigh…
Don H.
camaro:
That is a beautiful structure! Very well done.
Dave
Marlon, Dave Thank you.
Camaro- excellent workmanship. For structure purposes, the hot water immersion looks like the way to go. My heat gun OP is two- fold; one in the direction of rolling stock, where shallow angled covered roof pieces are required, the other with repect to structures where 90 degree bends would be more visually appropriate and less glue intensive.
I did pick up a metal seam bender plier from HF, in addition to the heat gun and extra nozzles. The jaws on the plier are 6 inches by a little over 1 inch, certainly enough for HO dimensional work.
Cedarwoodron
Comments reminded me of how an optometrist I visited as a teen soften plastic using a dry sand bath on a hot plate. It allowed him to submerge the part to be bent just long enough to soften. When shaped he would run cold water over part to set the bend. Would work well for model bending. Did a little web search on properties of styrene and it loois like the softening point is from about 212 to 225 F. Boiling water may work depending on formulation of styrene used. Almost any heat gun will put out air warmer than the sofling point. With experience and care, a heat gun would work but might result in lots of duds before success.
Well, I know my wife’s hair dryer can melt a DPM modular wall almost beyond recognition, and it does a great job with bending or straightening warped handrails. [:)]
Hi Camaro,
That is a beautiful job of modelling on that sturcture and the final setting for it does indeed put it right in Miami. Great idea and you certainly have impressed me.
Johnboy out…
Johnboy,
Thankyou for the compliments. I have been purchasing 4’x8’ sheets of .060 high impact styrene for quite some time from a plastics supplier in Grand Rapids, MI for quite some time. I find that I have better control with bending with thicker material.
If I remember correctly, I held each side of the plastic sheet and just dipped the middle in the water. I have never had much luck with heat guns and plastic tubing. This is probably why I went to brass rod for piping and such.
Larry
