I have a few kits with warped walls, some are plastic and some are resin (is this a form of plastic?). Any idea how to flatten them out before I try use them?
Appreciate the help,
John.
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I've used a hair dryer on low heat setting and I've also soaked them in hot water then laid something heavy on top of them until they cool down.
I use my wife's hair dryer, pretty successful but use caution.
Resin can be organic but most resins used in modeling is synthetic, some of which is oil based.
Put the walls on a flat baking pan in the oven at low heat. I put bricks on top but any non flammable weight should do.
I had mine in the oven for about 45 minutes but just make sure your parts get hot throughout.
Sean
Put the walls on a flat baking pan in the oven at low heat. I put bricks on top but any non flammable weight should do.
I had mine in the oven for about 45 minutes but just make sure your parts get hot throughout.
Sean
Although the following is from Alumilite, I 'spect their advice is fairly consistent among synthetic resins....
"Q: How much heat can Alumilite take before deforming or melting?
Alumilite will not melt. It will start softening in the mid 200°F and discoloring above 450°F. The shape and design have a lot to do with the physical resistance to heat. If there is no load on the part itself, it may soften at elevated temperatures but with no deform. However if excessive pressure or a load is applied, the resin may start to deform at lower temperatures."
So, about a year ago I cast some gothic church windows with their resin. The windows frames had a very thin cross-section, but they cast beautifully in the mold. I typically would wait a few hours before de-molding the parts, laying them on a flat steel surface (table saw table). Later I gathered up the 70+ windows of about 4 different sizes and put them into zip-loc baggies to store until needed during the church model construction. Big mistake!!!
Later, when I needed the windows, I found they had deformed badly in the baggies. In a panic I called Alumilite...Carol. She said "No problem! Heat some water to about 175 degrees, using a thermometer, and then dip each window into the water with some tongs. It will go limp....don't panic!! Simply lay the window down on a flat metal or ceramic surface. It will return to its original shape. Let it cool. You're good to go!"
And she was 100% right!! I was ecstatically amazed, to say the least!
Soooooooo.... I have no idea whether this would apply to your specific castings/resin. However, I think in general it would be safe to try the heating approach.
One thing I definitely would NOT try is using a microwave!!!
Been there, done that, .....bad, bad, bad experience. Granted it was with a styrene injection molded wall piece......which shriveled into a horrid ball of plastic in an instant!! Of course, I suppose if I had enough walls to experiment with power settings etc., I might have found a better MW solution, but the hot water worked so well, I'm satisfied with what I know works.
Been there, done that, .....bad, bad, bad experience. Granted it was with a styrene injection molded wall piece......which shriveled into a horrid ball of plastic in an instant!! Of course, I suppose if I had enough walls to experiment with power settings etc., I might have found a better MW solution, but the hot water worked so well, I'm satisfied with what I know works.Good luck. Let us know how it turns out....what you found what works
.....or doesn't!
.....or doesn't!KD
I had an extra O gauge Lionel observation car,2423, and wanted to make it in to a regular passenger coach. I cut the very end off so the sides were the same length as a coach, cut the walls from the floor, then using a hair dryer, I carefully heated the plastic, whatever it is, until it was soft enought to bend and form. Then after it was somewhat formed I laid it flat with weight on it, applied heat until soft and flattened the sides. Came out pretty good. I think you can control the heat much better with a hair dryer which is critical. A little too much and you have a big problem.
Originally Posted by dkdkrd:
Later I gathered up the 70+ windows of about 4 different sizes and put them into zip-loc baggies to store until needed during the church model construction. Big mistake!!!
Later, when I needed the windows, I found they had deformed badly in the baggies.
Interesting. Wonder why that happened......not 100% cured or what? Something outgassing in the baggies?
Originally Posted by mwb:
Originally Posted by dkdkrd:
Later I gathered up the 70+ windows of about 4 different sizes and put them into zip-loc baggies to store until needed during the church model construction. Big mistake!!!
Later, when I needed the windows, I found they had deformed badly in the baggies.
Interesting. Wonder why that happened......not 100% cured or what? Something outgassing in the baggies?
Martin...
Well, per Carol it's quite simple. I didn't store these items, having a very thin cross-section, as well as I might have. The gothic windows have a 'T' cross-section of about 1/8". Even if they've sat for a few days (they had.) on a flat surface, and would seemingly be fully cured, if they're then stored as a jumbled group (they were) in a baggie, the pressure points...though not very forceful...will, in time, cause the resin to relieve the pressure and assume a more neutral position....warped/twisted. In retrospect...lesson learned...the original fully cured castings might have been better stored on a flat sheet of, say corrugated boxboard, lightly taped down...in a gallon-sized baggie, if so desired.
Nonetheless, it's a common occurrence to the folks at Alumilite, for which they have a common, easy solution...warm-to-hot water.
This thread has become a bit of an embarrassment for me. I built this church about a year ago from an article in a 1930's magazine. I've been meaning to post a story/photos about the build, but have kept putting it off, putting it off. Maybe this current discussion will spur me into action.....after I get back from York, of course.
Later...
KD
Originally Posted by dkdkrd:
Originally Posted by mwb:
Originally Posted by dkdkrd:
Later I gathered up the 70+ windows of about 4 different sizes and put them into zip-loc baggies to store until needed during the church model construction. Big mistake!!!
Later, when I needed the windows, I found they had deformed badly in the baggies.
Interesting. Wonder why that happened......not 100% cured or what? Something outgassing in the baggies?
......I didn't store these items, having a very thin cross-section, as well as I might have.
Nonetheless, it's a common occurrence to the folks at Alumilite, for which they have a common, easy solution...warm-to-hot water.
Hmmm..... I've never had this happen. And, I have a drawer and a few boxes of castings - entire trolley car ends - just idly resting there not stored flat now for years in some cases.
I have to wonder how much of a consequence this is related to the resin itself; I stopped using their resin several years ago.......
I think the recommended flattening SOP for those old Chooch freight car parts was a low heat on a flat surface............and/or donating them to a trash can.
