Sand, coat, blush, rinse – repeat.

Pathfinder project jobs – November 2021.

For those who are interested, a new Facebook page ; the backyard boatbuilder :

Blog time ; 4pm on a dank and cold November afternoon, it’s been overcast all day and now what light there was is fading so iv’e packed up for the day. As i write it’s near the end of my second week of mostly hitting the garden work with just a few hours of boat work ; so far iv’e cleared the greenhouse, ‘spring’ cleaned downstairs in the cottage, weeded the veggie beds and so far planted a couple of hundred spring bulbs. The other daily routine i have is to walk up the back lane to where there’s been some early leaf fall and rake up a bag of oak, beech and sycamore leaved to use as mulch….just down the road there’s a stunning red maple about to drop it’s load as well and that looks great as a top layer .

On the Pathfinder build iv’e been adding lots of detail, mostly adding all of the doublers and bearers that support the cockpit seats aft and the bunk flat forward. At the end of the week i patterned and then made 2 of the 3 cockpit seat tops but then didn’t have a piece of plywood wide enough and long enough to make the last one so i’ll have to wait for dry weather and go get another piece. Until i start working on the foredeck. side side decks and coamings that’s the last big pieces all cut out now so ‘main construction’ is now mainly about getting all of the inside sealed (epoxy coated) , cut back and then all of the compartment spaces primed and painted. I can do that now that iv’e got a more reliable way of heating the space inside the tent so epoxy curing and painting should be feasible.

Most of the winter mulch on.

Epoxy coating.

For this post i just want to talk about the main work that iv’e been doing, on and off, for several weeks now – and that’s laying on several coats of epoxy resin to seal all of the inside of the hull. I did most of that as i went along – the frames and bottom board for example when it was very easy to get them in that i could stand close in between the frames . When i fitted the stringers and then the planks i did the coating of those in 2 stages….the bottom 2 planks first when it was still relatively easy to get at them and then i finished everything once i had the top 2 planks in and by then i was often having to stand on my step-up and lean in over the top stringer. The big problem that i had at the end is that after a long day of coating almost all of the inside portside (finishing coat low down and first coat on the upper planks) i didn’t realize but my fan heater must have packed up soon after i covered the boat over and the next morning i found that all of the epoxy coat had a waxy finish….an Amine blush.

Some say that the ideal way to coat plywood with epoxy resin is to apply one coat, let it get to a certain stage of cure and then apply a second coat which will then chemically bond with the first one. The other approach is to coat the plywood, let it hard-cure and then abrade it back enough to let the next coat adhere properly ; in my case i’d run out of working time that day and the coat that i’d applied would have taken several hours to get to ‘gel’ stage. The next morning i went to sand the cured epoxy back a bit and i found that my sandpaper clogged almost immediately with a brown waxy substance – the amine blush. I persisted with dry sanding for a couple of compartments but found i was using sheet after sheet of fresh sandpaper, essentially just wasting it – so i thought again and changed over to 80 grit wet and dry paper used wet with warm water and a small amount of detergent. Aside from fingertips so sore that i couldn’t even tap the keyboard that night the wet sanding technique worked well and it also allowed me to wet wipe the whole boat out ; it’s at that stage where i want to keep the whole of the inside clean for priming and painting now.

Incidentally i finished the wet sanding stage with blowing warm air over every surface and into every nook and cranny using my brand new hot air gun coupled with a soft brush to sweep out any paint and epoxy dust debris. That plus a second wipe over with clean fresh water and a final dry vacuum out left a good finish to coat over…..except that i’ll have to now sand out the whole of the inside ready for priming !

The nice side of this week’s work was some time spent marking out where all of the forward inspection and access hatches are going and cutting out the holes for them…..12 holes so far. Iv’e also been playing around a bit with where stuff is going to – the day water container for example ; most of the drinking water will be in Dromedary bags under the sole board of the central compartment.

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