This wiki article explains how you would prepare for a tube overwrap layup. The specific quantities listed are for the 3" Phoenix fin cans, and the layup space is in Gelb. Preparation takes anywhere from 1-2 hours if you count kitting, but if there's one thing this team can learn from Prof. Drela, it's that preparation is the most important part of the layup. You can literally save hours of time and frustration if you've properly set up your layup. 

For instructions during the actual layup, see Hermes III Fin Can#3: Dusty Fly Trap

Supplies

You'll want to lay them out beforehand on the supply table so they're easily found. Time wasted finding supplies after you've mixed epoxy is bad. We want to vacuum before we hit pot life of the epoxy on the part. 

  • Systems 3000 Resin and Hardener (check those quantities are reasonable for a layup)
  • Squeegees 
  • IPA 
  • Shop towels 
  • Extra-long globes in all sizes 
  • Back up regular gloves
  • Vacuum connector (check that it actually connects) 
  • Vacuum (check oil levels)
  • Scale (check to make sure it works)
  • Epoxy cups 
  • Popsicle sticks (or something to mix with) 
  • Wax paper 
  • At least 2 tables 
  • Tube (sanded, cut) 
    • Low grit sandpaper (40? 60? something to roughen)
  • Full kit (see next section) 
  • Pole (or layup jig for tube) 
  • Butcher paper (or sacrificial wax paper, basically something to cover the floor/table so epoxy doesn't ruin it)
  • Carbon fiber scissors
  • Highly recommend: a speaker to play music 

Kit

Overwrap Kit Material
Sizes

High temp vacuum bag (pink, no holes)**

OR shrink tape

 
Breather cloth (white, fuzzy) 
High temp peel ply (blue nylon or white polyester) 
High temp release film (red with holes) 

Carbon fiber (3 layers, (0/90))

 
Wax paper 

 

If you have a bunch of extra hands, you can leave some things to cut during the actual layup. However, you really want to avoid a wet, fully laid up part sitting and waiting for breather/vacuum bag/peel ply etc. Again, you're burning your pot-life time. 

 

Location

This picture is for a tip to tip layup, but the idea for an overwrap is pretty similar. Basically, clear the paper on several tables, rest your fin can on a jig or pole. Make sure you've covered the area with wax paper and properly labeled tables with MIT Rocket Team (that way if you leave while you're setting up, you won't lose your table to someone else). Have supplies clearly laid out on a table. Have an area for dry plies and wet plies. Have a spot for all the prekitted materials. 

People

An overwrap layup isn't as time or labor-intensive as a tip-to-tip. You should have at least 3 people at all times. If people can't stay the entire time, try to assign shifts. This was you won't have too few (or too many which can also be bad). Once you start mixing epoxy, the layup should only be an hour or two. Assuming you're prepared. 

Try to vary tasks so that someone isn't literally pouring epoxy the entire time. 

Tasks to assign: 

  • Epoxy mixer
  • 1-2 people laying up 
  • 1 person kitting materials or preparing bag 
  • someone cleaning hella things 
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