Thursday, December 05, 2013

More on Papier-Mâché nose cones - you will be bored if you read this (updated)

A few days ago I mentioned that I had become interested in making rocket parts (i.e. nose cones) with Papier-Mâché. The goal would be to make them cheap and expendable but not necessarily perfect.

Here's my first experiment. Since I didn't have a suitable mould I decided to cast one in a scrap piece of 29mm tubing. So, I mixed cellulose insulation with Modge Podge (thin white glue). I added dog barf until the mixture was moist but not dripping. I tamped it in using a dowel and then compressed it with two used 29mm motor cases. I left an longer overhang on one end so I could add a shoulder. After both ends were dry, I peeled most of the tube off. Not unexpectedly, I found there were voids. I think the lesson learned is to tamp in smaller quantities, possibly letting each batch set before adding more. 

Just to make this nose cone-like, I rolled the tip to thin it and then hung it upside down to let it dry. After a day and a half, this is what it looked like. Looks like it should be floating in a pool in an old John Belushi movie. In addition to the voids, there was also significant shrinkage. The lesson here is probably that Modge Podge isn't the best binder for this application.

This is ~3.5" long and weighs 1.15oz (before filler and a shoulder). There is still masking tape on the 29mm tube that forms the base of the cone (to ensure it matches the tube perfectly). I have applied a thick coat of fill'n'finish, mainly because I don't have any other indoor rocketry projects to work on. (My reconfigured, ex-Talos is awaiting primer that I don't have yet.)

Status 12/11/2013: Effort on this cone has been cancelled!