Making good progress on my Pygmy Borealis kayak! The bulkheads were fitted and then fiberglassed.
Fitting the bulkheads is one of the trickier tasks. There are several methods you can try, but most involve trial and error, and nipping small bits away over and over. Just stick with it.
I start by using cardboard cutouts of the bulkheads that come with the kit. Just trace around them and cut them out. Also cut finger holes in the cardboard so that you can maneuver the templates in and out of the hull. Try to fit them by seeing where they need to be trimmed, marking those areas, trimming the cardboard away, and repeating until you get a cardboard template that fits reasonably well.
Below are the cardboard templates. Notice the finger hole cutouts. The tongue depressors are glued to the stern template to the actual edge where I cut too much and had a large gap. Just hot glue some tongue depressors or cardboard in place where you have a large gap, and then transfer that line to the actual bulkhead for trimming.
Then trace the template back onto the plywood bulkheads. The bulkheads come a bit over-sized for just this reason. Once the bulkheads have been trimmed (use a band-saw, jigsaw, or if not much needs to be trimmed then a stationary sander works well too) you will most likely need to trim them again too to fine tune the fit. Don't be too concerned about gaps or large spaces between the edges of the bulkhead and the inside of the hull. Most of those will be filled with thickened epoxy.
Bulkhead Pressure Relief Holes: In these pictures you can see a 1/4" hole in both bulkheads near the top edges. When the other side is fiberglassed I will also fill the hole with epoxy. Then when cured I will take a #60 bit (0.0400"/1.02mm) or no larger than a 1/16" bit, and drill through the middle of the epoxy. This will create a fully sealed air release hole so that the hatches don't get too suctioned down and can be easily released.
The reason for the larger hole first is that it is pretty impossible to drill such a small hole and to get it sealed. This is quick and very easy.
Before you fiberglass the first side of the bulkhead, simply drill a larger hole. I used 1/4" but use whatever. Then fiberglass the bulkhead. Let dry. Trim the edges once the epoxy reaches the "green stage" but do NOT trim the hole. Flip over and get ready to fiberglass the back sides. Before you lay out your cloth simply fill the hole with epoxy. Lay your cloth on top and wet out and squeegee normally. Let cure. Drill a very, very small hole directly through the middle of the larger hole filled with cured epoxy.
The lettering in the picture above is simply a laser printer transparency sheet. I typed up the words, ran it through my laser printer, and cut it out as closely as possible. Then I spread out some epoxy on the bulkhead and carefully laid out the cutout onto the epoxy and pushed the air out. Then I put the cloth on top and wetted it out normally. Yes... it's a bit crooked! Ugh. And it's not helped by the fact that the grain runs crooked too and makes it look more angled than it really is! Probably only noticed by me once it's in the hull, but still.... Erf!
I ran out of hardener on, luckily, the last part of my last pump. Ugh. Ordered another 3 quarts (1 qt. hardener, 2 quarts resin) from Pygmy. Hope it arrives soon. Lots of small batch jobs to do!
Peace!
Fitting the bulkheads is one of the trickier tasks. There are several methods you can try, but most involve trial and error, and nipping small bits away over and over. Just stick with it.
I start by using cardboard cutouts of the bulkheads that come with the kit. Just trace around them and cut them out. Also cut finger holes in the cardboard so that you can maneuver the templates in and out of the hull. Try to fit them by seeing where they need to be trimmed, marking those areas, trimming the cardboard away, and repeating until you get a cardboard template that fits reasonably well.
Below are the cardboard templates. Notice the finger hole cutouts. The tongue depressors are glued to the stern template to the actual edge where I cut too much and had a large gap. Just hot glue some tongue depressors or cardboard in place where you have a large gap, and then transfer that line to the actual bulkhead for trimming.
Then trace the template back onto the plywood bulkheads. The bulkheads come a bit over-sized for just this reason. Once the bulkheads have been trimmed (use a band-saw, jigsaw, or if not much needs to be trimmed then a stationary sander works well too) you will most likely need to trim them again too to fine tune the fit. Don't be too concerned about gaps or large spaces between the edges of the bulkhead and the inside of the hull. Most of those will be filled with thickened epoxy.
Bulkhead Pressure Relief Holes: In these pictures you can see a 1/4" hole in both bulkheads near the top edges. When the other side is fiberglassed I will also fill the hole with epoxy. Then when cured I will take a #60 bit (0.0400"/1.02mm) or no larger than a 1/16" bit, and drill through the middle of the epoxy. This will create a fully sealed air release hole so that the hatches don't get too suctioned down and can be easily released.
The reason for the larger hole first is that it is pretty impossible to drill such a small hole and to get it sealed. This is quick and very easy.
Before you fiberglass the first side of the bulkhead, simply drill a larger hole. I used 1/4" but use whatever. Then fiberglass the bulkhead. Let dry. Trim the edges once the epoxy reaches the "green stage" but do NOT trim the hole. Flip over and get ready to fiberglass the back sides. Before you lay out your cloth simply fill the hole with epoxy. Lay your cloth on top and wet out and squeegee normally. Let cure. Drill a very, very small hole directly through the middle of the larger hole filled with cured epoxy.
The lettering in the picture above is simply a laser printer transparency sheet. I typed up the words, ran it through my laser printer, and cut it out as closely as possible. Then I spread out some epoxy on the bulkhead and carefully laid out the cutout onto the epoxy and pushed the air out. Then I put the cloth on top and wetted it out normally. Yes... it's a bit crooked! Ugh. And it's not helped by the fact that the grain runs crooked too and makes it look more angled than it really is! Probably only noticed by me once it's in the hull, but still.... Erf!
I ran out of hardener on, luckily, the last part of my last pump. Ugh. Ordered another 3 quarts (1 qt. hardener, 2 quarts resin) from Pygmy. Hope it arrives soon. Lots of small batch jobs to do!
Peace!
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