April 29, 1997 2 hours: Unload aluminium. Check order, 5" pipe damaged, 3" heavy wall pipe damaged missing 7' sch 80 3" 3' sch 80 2" and SS tubing
May 8 1 hour: Move 3/16 plate to work area
May 10 10 hour: Layout bottom plate from computer lofted patterns. Cut out with plates stacked 2 thick.
May 14 2 hour: Print out patterns for front of lower hull sides.
May 16 4 hour: Setup MIG welder ( Miller Regency 250 and 30a spool gun ). Back and forth with metal supplier re Test Certificates on 3/16 bottom plate. Test cert shows only H32, agree to independent test to validate H116 compliance and send sample off.
May 17 4 hour: Print out patterns middle of lower hull sides and bow cone. Clean bottom plate and position in assembly area. Make up some samples and try out various weld settings. Trying grooved steel backup bar for butt joints.
May 18 5 hour: Practice butt welding 3/16". Some settings that seem pretty good .047 wire 24V 5.25 feed. .030 wire 20V 6.0 feed. The 24V has a nice cleaning action with a nice buzz and no large globs in the transfer stream. Also got some practice cutting out the back of the weld, want about 3/32" cut back. Will probably leave bead on in interior. As expected the plate 'V's toward the final weld side and bows toward the final weld side along the length of the weld.
May 24 5 hour: More Practice butt welding 3/16". As I am building outside the wind has been a problem with it blowing away the argon. I have rigged up steel Tbar posts and tarps around the immediate work area and this seems to control the problem, am now getting shiney beads with no visible oxide dross. Tried some .035 wire as the bead is smaller and the heat input less. Best results are using a 1/16" gap on the initial pass, with 1/2" tacks every 6" then filling in reverseing direction and letting it cool between each section. Im using a steel backup bar and this results in a full penetration weld for the most part. I then cut back about 3/32" with the skilsaw for the back pass which is also done in sections.
May 25 2 hour: More Practice, did 4' butt weld. Good quality some distortion along length. Using .035 wire at 24v 5.5 feed and lots of argon this may be contributing to spatter alongside weld.
June 7 9 hour: Well the rain finally stopped after two weeks. Cut out forward part of lower sides from 5/32 plate.
June 8 8 hour: Cut out lower sides middle and re-arranged shapes storage.
June 9 1 hour: Draft out lower sides aft and cut out some of them.
June 10 1 hour: Finish cutout of aft lower sides.
June 14 8 hour: Move side plates for assembly of port hull port side. Test welding .030 22-24v 7-8.5 feed. High feed gets rid of spatter and has improved cleaning action. Welds still a bit drossy. Not bad but some dross on fusion line. May be grade of argon ( industrial ) will order up some 'High Purity Plus' which has <5ppm H20 rather than industrial grades <10ppm.
June 15 8 hour: More testing, getting good 5/32 butts with .045 24v 5.25 feed and backchip side .030 22v 7.5 feed. I am able to get consistant quality with full 180 bend without failure. *** Did first weld on the boat*** Aft lower side butt. Did not support backing bar high enough so there is slight sag ( also from weld shrinkage ). Fit up got out to 1/8" on this piece. Welded alternately and checked lengthwise alignment after each weldup.
June 16 3 hour: Weld up forward butt of lower side. NOTE remember to work from centre out to edges on all welds to avoid pinch in at centre. Line up method working good, maybe 1/16" out in 20'. I line up by striking a line on each plate from the notches put in when they were cut from plate. I put a 20' 1/4"x4" 'ruler' on the lines of the two plates and line them up clamp and tack them. I keep this as a reference during the butt weld up. Started fitting hull stringer for lower side and sniped long snipes of 12" for when ending on skin ( like near the bow cone ) and 4" snipes for ending just after a frame ( aft lower stringer ). Started raining at 10:00.
June 10 1 hour: Finish cutout of aft lower sides.
June 17 5 hour: Cut snipes and cut to length on all lower hull stringers. Did some test welds on offcuts to figure butt weld requirements. This is 6061T6 stuf so will probably leave some bead on.
June 19 11 hour: Test butts in hull stringer, settle on .030 26v 10 feed on inside. Do bottom of channel first then tack 2 outside corners, then the two insides sides of channel ( turned for on the flat welding ). Back cut about 1/8" off outside then .030 22v 8.5 feed on top then each side again on flat. Leave bead on. In a notch shear test the beads neck down considerably. Joined up 1 set of stringers for lowers and tacked on about 15' in centre panel, working from the centre out evenly on top and bottom. Piece of 3/16 backup plate but still getting mild print thru. Using .030 24v 10 feed. Will try .030 22v 8.5 feed on stern section to see if it gets rid of print thru ( smaller cooler bead ). Argon down to 400psi in small bottle. High purity stuf is not in yet so will get a large bottle of the regular for the weekend.
June 21 5 hour: Loft outside panel parts. Stitch rest of middle panel on lower side and turn over. Some washboarding on the stitch area. Change, plan to only tack up every couple of stitches and finish stitch up after bent to shape. Best filet setting is .030 22v 10 feed.
June 24 9 hour: Rain over. Finished tack up of lower side using just alternate stitch zones. Full stitchup on lower stringer + at the ends of upper stringer ( tough to weld these after panel assembly). Finished weldout of outside panel. ( would be nice to do with backing bar + no stringers). Moved stb hull port lower to assembly area for joining up bottom panels.
June 27 2 hour: Build rain shelter over work area 24x18 tarp and 24' Tbar on steel Tposts.
Copyright © 1997 Tony Bigras.