Tuesday, May 8, 2012

MattMobile Front Turbine Nozzle Work Begins

It's time to start doing some body work on the MattMobile. In order to test my materials and techniques, I'm going to officially kick things off by working on this piece, the turbine nozzle.

It's a fairly decent fiberglass layup, but has the typical problems that you would find on a piece like this. It's got a seam that needs to be filled and levelled, and a number of surface blemishes and pock marks. As always, absolutely no disrespect intended to the maker of this piece. It's a fine piece... but it's a kit. It needs work.

With that out of the way, I'll walk you through my first steps.

For reference, this is the fiberglass resin I typically use. It's a bunch more expensive than the polyester stuff you will find at home depot, but guess what? It's a bunch better! This is epoxy resin, which basically means it doesn't stink to high hell the way polyester resin will, and in my experience it is a bit stronger. It also cures very clear, with a slight amber tint.

However, also for reference, this stuff does have a fairly unforgiving mix ratio. On my first batch, I just emptied out what was left in my previous kit, assuming that I would have the proper amounts left over in the cans. Bad assumption. One great thing about the west systems resin is that they mix on a 10:1 ratio, which can be achieved super easily with the pumps they sell. One pump from each can and you get the proper ratio. This mess you see here is what happens when you get the mix ratio wrong. I should point out that in all my years of using this product, this is the first time this has happened.

But where were we! The first thing I did on the nose cone was mix up a tiny batch of resin, and then brush it into the seam. The goal was to fill in the seam gap, as it was non trivial. In retrospect, I probably should have just gone straight to putty, but since I'm experimenting, it seemed fair. I should also point out that prior to laying in the resin, I roughed up the surface with some low grit sand paper to give the resin something to tooth on. Honestly, this particular resin is super tenacious, and it probably wasn't necessary. However, it can only help.

Here's the bottom of my mixing cup, showing the color that the resin cures in.

That's it for the first day. The cure time on this stuff is about 24 hours, though pot time is much shorter. After the first side toughened up a bit, I did the other side, then let it cure for the night.

Next post, I attack with sanding gear and putty!!!

No comments: