I always fill my spirals (using thinned CWF) but I certainly don't enjoy it. For my current build I needed to fill a 22" tube and I decided to see if I could improve my technique to speed things up. My results were... well, fantastic. Thought I'd share. I have no idea if this is what everyone else is already doing, but it doesn't match the pictures or descriptions I've seen posted before.
Start by getting a small glop of CWF on your finger. Spread it messily around (roughly) one rotation of the body tube (quick and dirty is the key). Note that this particular tube seemed to have no secondary spiral, so I only needed to deal with the primary. The black spiral is not indented, or if it is it will be taken care of by filler/primer.
Next I used a credit card and squeegeed of the excess. I kept the card perpendicular to the tube, pressed it down pretty hard, and rotated the tube slowly and carefully. After doing a bit wipe the card on a paper towel.
After this step there was *very* little excess on the tube, and it dried in barely a minute or two. Continue along the entire tube.
Finally I sanded with *800 grit* around the spirals. There was blessedly little to sand and the 800 grit made quick work of it without ruining the surrounding glassine layer. The result:
I did the whole 22" tube in about 5-10 minutes (I would have timed it if I had realized it would be so quick), and there was so little sanding it was glorious. As far as I can tell, the spirals are filled just as well as any other time I've done it more laboriously, and there are absolutely no excess CWF bumps.
The two key improvements for me were:
1) Applying the CWF roughly by hand. Very quick and easy.
2) *Vigorous* removal of excess filler with the credit card to minimize subsequent sanding.
Start by getting a small glop of CWF on your finger. Spread it messily around (roughly) one rotation of the body tube (quick and dirty is the key). Note that this particular tube seemed to have no secondary spiral, so I only needed to deal with the primary. The black spiral is not indented, or if it is it will be taken care of by filler/primer.
Next I used a credit card and squeegeed of the excess. I kept the card perpendicular to the tube, pressed it down pretty hard, and rotated the tube slowly and carefully. After doing a bit wipe the card on a paper towel.
After this step there was *very* little excess on the tube, and it dried in barely a minute or two. Continue along the entire tube.
Finally I sanded with *800 grit* around the spirals. There was blessedly little to sand and the 800 grit made quick work of it without ruining the surrounding glassine layer. The result:
I did the whole 22" tube in about 5-10 minutes (I would have timed it if I had realized it would be so quick), and there was so little sanding it was glorious. As far as I can tell, the spirals are filled just as well as any other time I've done it more laboriously, and there are absolutely no excess CWF bumps.
The two key improvements for me were:
1) Applying the CWF roughly by hand. Very quick and easy.
2) *Vigorous* removal of excess filler with the credit card to minimize subsequent sanding.