How To Build And Use A Steam Box
Geodesic Airolite Boats (http://www.gaboats.com)
STEAM RIBS WITH GREAT CARE TO AVOID BURNS. WEAR A SAFETY MASK& GLOVES - STYRO FOAM IS VERY FLAMMABLE SO BEWARE. The ribs can be water soaked for bending but steaming is by far much more satisfactory. A simple steaming rig is easy to make, using PVC drainpipe and a large kettle. We have used this technique with various configurations, however on the last go around when we were ready to go, suddenly, it was discovered that the rig was too short for the ribs. I remembered a casual mention about someone using pink Styrofoam for a quick and dirty steam box. We tried it with outstanding success. Run the foam board through the table saw very carefully to avoid tool marks for a tight seal. (some wool knitting yarn laid in the joints will make an ideal caulking) The box needs no gluing or goop in the joints, just wrap some duct tape around it to hold it together. (we used rubber bands about every 6 inches)
Support the box on chairs or whatever (protect from water drips if necessary) and block it so the pipe fits in place. Notice the slight incline from the steam inlet to the removable plug. Start with a kettle of about 2" hot water. Use a camp stove, hot plate or the kitchen range. Adjust the heat to just maintain some steam leaking at the removable plug end.
Note that the edges of the ribs should be sanded (prior to steaming) to remove burrs and splinters otherwise they will be likely breaking points when you bend them (steamed, soaked or otherwise). Add a couple of small wooden blocks to the inside of the steam box so that the ribs are up off of the bottom. Place about 6 ribs in the box at a time. Spread them out so the steam gets at them all around.
The foam box immediately demonstrated its advantage over the pipe when the steam came up. The insulation factor kicked in and we saved about a half-hour waiting for the pipe to heat up. It was amazing how steam tight the non-sealed box was.
Leave the ribs in about 10 minutes. Wear leather gloves and remove one and work very fast. The first initial bend should be to over bend and form a circle. Slip this inside the hull and then shape it to fit in place. You will discover that the working time is about one minute; then it will lock up tight. If you feel that you have goofed on the fit you can remove the rib and it will be easy to straighten. Now simply re-steam it for another try. As you remove ribs, add more to maintain a steady flow of stock.
This is another two-person job, you definitely need that person on the other side of the boat to do fitting before the rib cools.
DO NOT LEAVE THIS KIND OF A RIG UN-ATTENDED AS IT IS OBVIOUSLY
A FIRE HAZARD - BE SURE TO WATCH YOUR WATER LEVEL AND SECURE YOUR
STOVE TO AVOID TIPPING
|Copyright 2002 Monfort Associates.|