Monday 8 April 2019

Tack Welding | Securing The Transom

The first tack welding session was more about learning how to do it effectively rather than get a lot done, so I practiced on the joins which are easy to reach - the chines.

I started off using a large food freezer bag as a dispenser. It worked OK but dispensed a lot of epoxy in one go, and it was starting to go off by the time I had finished smoothing out the tack welds with a filleting tool.

So I downsized to a smaller bag, and that worked well too.

Lastly I tried out a piping bag, as used by bakers and the like. This worked really well, being designed for the job and staying quite rigid in use.

I finished the chines and left them to cure.

I had been concerned that the build manual is silent on how to secure the transom in place. The assumption is that epoxy fillets and 'glass cloth will do the job, leaving a dry joint between the transom and the hull. I tend to doubt that this approach would suffice, especially in extremis when you really don't want to be wondering if your transom is about to fall out. I decided that a proper glued joint was required.

I therefore backed out the temporary screws holding the transom in place on the port side, filled the gap with thickened epoxy, and tightened up the screws again.

I repeated the process on the starboard side.

Finally I drilled and countersunk pilot holes and screwed the transom firmly in place with 1" 8 gauge silicon bronze wood screws. Three screws in each side and five in each bottom panel. Here is the transom, securely fastened in place.

That transom is not going anywhere!

There then followed several hours of rather tedious tack welding, using the piping bag. It worked well, even when I was leaning over to reach the centre and bottom of the boat. It doesn't hold much epoxy though, and I will need something much larger to do the fillets.

Here are some of the tack welds on the hull, floors and bulkheads.

And here they are in the bow.

The best part of this task was finishing it. I will now leave the boat for a few days to fully cure before I pull out the stitches and start filleting.

No comments:

Post a Comment