"The white rubber has additives and colorants in it that reduce the life. For a longer lasting shock cord, ditch the Estes stuff and replace with model airplane rubber motor stock. It is tan color, much more pure and lasts a really long time by comparison. In the old days Estes actually used it. Check out www.faimodelsupply.com - they have 1/16 through 1/4" width, and it's not that expensive, 32ft of 1/8" for $3 and change. Or you can buy a 1 lb. box for a near lifetime supply.
Or try decent sewing elastic which also has pretty good life and fails more gracefully by losing its stretch rather than abruptly breaking. Some people don't like it but I've always had good luck with it, and it will not zipper your model."
For the 1/8" x 32' package, here's the web page: CLICK HERE
32 feet of 1/8" real rubber shock cord for $3.65. Not a bad deal.
"The white rubber has additives and colorants in it that reduce the life..."
ReplyDeleteThere is an equivalence to this with whitewall and gumwall (tan) bicycle tires. Whitewalls are pretty but they tend to dry, crack and crumble. Gumwalls last longer and give a better ride, but they get a little "gooey" with age. Standard blackwalls give a harder ride but last way longer.
I also prefer sewing elastic, but after having flown a few second-hand rockets with rubber cords, I wouldn't mind trying this tan cord just to see how well it holds up.
I found this stuff Chris with a quick Google search: http://m.ctsusa.com/_e/Braided_Elastics/product/ELASTIC-0418W/1_8_White_Braided_Elastic_Roll_288_yds.htm
ReplyDeleteThey offer a couple free samples with a SASE. I think I may try it.
Hi Vilgilate,
DeleteI use elastic for most of my builds. I did this post for builders looking for the old style rubber shock cords.
I buy my elastic shock cord (for the Odd'l kits) from them already!
On the CTSUSA website it seems less expensive until you add on the shipping charges.
For the same stuff, do a Ebay search under:
White Braided Elastic 1/8" Roll 288 Yards
Look for the CTSUSA name.
On Ebay it's a few dollars less in the end.