Sunday, 19 August 2012

Lessons learnt from frames to strongback

I will add to this as I think of more but so far:

Follow the plans exactly - I saved some wood by not continuing the solid frame sides up higher to attach the temporary cross piece.  This cost me lots of time, heartache and extra work in the long run as I had to buy more wood to support them higher.

Mark everything when on the drafting floor - some of the frames I missed the waterline and it was a pain to try and confirm them.  It is also an opportunity for errors to occur.

Take your time with the frames - mine worked out fairly well and were level in each direction when they came off the floor.  This makes it much easier when the time comes to line them all up, and it helps your confidence no end when things start to go right.

Measure twice, cut once - everyone knows this one, thankfully I only had to remake the solid wood for one frame.

Closely related is measure twice, screw once - as I was standing up the frames and moving them up and down each side I lost count of the times I had to remove screws because I had forgot to check something.  Get it where you think it needs to be, then double check EVERYTHING before you screw it in place.

Standing up the frames - lots of clamps and take your time.  Start with the centreline on the frame matching the centreline on the strongback.  I used wire down the strongback for the centreline, then string and a weight to get the frame in the right spot.  Use string from the centreline out to the sides of the frame to confirm they are at 90 degrees (the length of the string should be the same).

Keep your level close to hand - always keep checking levels in each direction.  A little move one way can throw out other parts of the frame.

Don't forget to duck and lift your feet - as you move side to side and through the frames there are very hard pieces of wood at shin height and also some plywood stuff just at head height out of view.  Trust me, it hurts!

Eat and Hydrate - keep water close at hand and drink often.  Sounds simple but several times I got lost in the work and realised at the end of the day I was very thirsty.  I also found sometimes I needed to walk away and have a break when things were not going well.  Plus you get to look at what you have achieved so far which keeps the motivation up.

Frames standing up

With the assistance of an extra day off for the local show in Brisbane, and a rostered day off I had some solid shed time to get the frames up.  I will do another post after this one with the lessons learnt for those considering a build in the future.

But now time to gloat!

Started with frames 4 (galley front) and 5 (galley rear) as per the building instructions from John Welsford.  I spent extra time getting the frames at the right height from the strongback (1106mm) as all the waterlines etc are taken from here.  Once they were stood up you screw the 12mm ply galley front bottom piece (which is the top when you build upside down!) to stiffen the two frames.


And from the side with frame 3 in front:


Then I worked back from frame 5 to the transom.  Each frame was levelled vertically, horizontally and using a string and nail from the centreline was positioned at 90 degrees to the centreline (hopefully).  Below is 3 - 7:

Fr 3 - 7 from the front side:


Continue on to the transom which is actually 15mm above the waterline (below when building upside down) hence the packer under my string line to get levels right at the sides.  In front you can see frame 10 and 9 which is the solid one:


And from the side:


Once I got the transom done it was time to dynabolt the wooden ground supports for the stem and frames 1 -2:


Then I stood up frames 1 - 2:


You will see in the below photo some extra legs.  One of the lessons learnt is to follow the plans exactly.  Some of my frames needed to be raised above the cross pieces, but this actually worked out well because I could put in a vertical leg to take some of the weight and also support the frames:


Then this morning it was finish attaching frame 1, then cut the stem and glue.  This took much longer than I thought.  Below is the cut down stem:


Glued in place:


And from the side:


Once they were all up, I went along and nailed them to each other, across the tops and back to the strongback in a few places.  This took a while as I was checking everything again, below shows the ones across the top, the earlier photo of the legs shows one of the angle ones in the background:


And now, the final results.  Thanks to digital photos I can spin them round to right way up for the internal shots.

From a distance from the front:

Inside from fr 8 towards fr 1:


Frame 5 - 1 inside

Frame 6 to the transom:


Now have to organise the wood for the stringers.

Sunday, 12 August 2012

Strongback

First was the side pieces which were in two pieces each, joined with blocks inside and out and four 8mm bolts/glue per side. 



Then I clamped them close together and marked out all the places for the cross members for strength, marked the position of the legs and also the frames (measurements adjusted for my stretch).



Then I clamped all the cross members in place and screwed them into the sides with 70mm tech screws (two per side). This gave me the basic frame. 



Then I cut 10 legs 400mm long, and while upside down clamped them in place four at a time. I then checked the level each way including the ones already done, sideways, horizontally and also diagonal. I also checked each leg for level. Then I crossed my fingers and bolted them all to the sides with two bolts per leg.

Once I had finished all the legs, I flipped it over. 



A further two tech screws were put in per leg where the leg was underneath the cross pieces. This was at each end, and one of the legs in the middle.   The final step was a 9mm ply end piece glued and screwed to the legs each end, the sides and the cross piece.  There is one of these on each side at each end to provide bracing.




From the side below, four tech screws 70mm long from the top, two 8mm bolts from the side through the leg and side piece, plus the ply and screws/glue from the front.  Hopefully strong enough....




The final check was level along each of the sides at various points, then each of cross braces. Below is the result, with help from my assistant (and the blokes who laid the level concrete slab for my shed, I owe them a beer).

Side pieces:



Cross pieces:

To give me an excuse for a beer, I stood up frame 3 ( it is too low but looks the part!).



Onwards to standing up the frames, have to borrow a laser level.

Transom finished.

Transom is done, no more frames!! This one finished above the waterline.

The frame has a doubler on the forward side, a 30 x 45mm cross piece to support the cockpit floor (half lapped into the frame so the transom has one flat vertical surface for the ply transom) and two vertical 30 x 45mm pieces for the seat front support. The laminated beam is only dry fit at this stage, and there is another laminated beam to go across from the very top for the aft deck.




Once the cross piece was done, the vertical supports for the seat fronts were positioned.



This is a close up of the solid frame, horizontal and vertical pieces all half lap joined. All epoxy glued in place, I skillfully left nice spaces in the joins to allow the epoxy to get a good penetration! They are not as bad as they look, trust me.



It was glued with everything in place, but not all was glued.  The laminated beam to the frame and the laminated beam to the upright were not glued.


This is the final result from forward side:


And from aft, all flush finished so the ply can go on.