The only rough edges on our fascia panels were where the runs finish at the gable end. There are two on the north end and one on the south – the east run of fascia ends against the stub of wall that extends out from the gable end. Ric filled in the ends with bits of fascia board then cut covers from a sheet of aluminium. They wrap under the bottom of the fascia board as the panels do, but have flaps that fold round the right angle over the adjacent panel and over the top onto the sarking boards.
We coated and cooked them along with three joiners to cover where these covers lap over the panels. We coated them whilst it was raining heavily and whilst the primer went on well, the top coat was very unsatisfactory, with a lot of spots of primer showing through. We left them a couple of days and re-did them when it was warm and sunny, it all went much better and they were all fit to put up. It was a quick job to hook the covers over the bottom of the fascia board and nail through the top flap. Then we lifted the eaves trays out of the way and nailed the joiners across the join between cover and panel. Very neat.
We finished making the remaining powder-coated fascia panels we need for the north and east wings, 9 for the north side of the north wing, 6 for the east side of the east wing and a short one for the stub of fascia for the west side of the east wing, on the north end. It went smoothly enough, with fewer re-coatings needed as we improved our handling of the un-cooked panels – around three days work to cut and fold the panels, clean them, spray them with primer, cook them, spray them with top coat, cook them, make the joiners from aluminium 2” x 1/7” bar, coat them, install them and install the eaves trays above them. The joiners covered much better than with the first batch, I needed to recoat only two of them. Again, it really improved the appearance of the fascia.
With the aluminium
folder, the powder sprayer and the oven all working, we pressed ahead with
creating all the remaining dozen panels we needed for the north and east wings
on the courtyard side. We processed them in pairs, more than that and I
struggled to lift them in and out of the spray booth without brushing them
against me or the spray booth. Indeed the biggest problems throughout were
caused by poor handling. Two panels had enough defects that I recoated them, which
was OK, but did not produce as even a finish as the first topcoat.
I noticed
that the resin primer powder behaved quite differently from the polyester top
coat. It was easier and quicker to spray on in even coats and I could cover
three panels from one bottle of powder. The top coat took longer to apply, was
more liable to blow out of the sprayer unevenly, took a higher airflow setting
and used half as much again as the primer – two panels per bottle. I did get
better with the spraying, but in fact the process was quite forgiving – it was
not difficult to get a good finish. I bothered less about the top section of
each panel, which would be under eaves trays and slates, working for best
results on the bottom half. With a 90 minute cycle time to clean, spray, load
into the oven, cook, cool and remove, we could get 6 panels a day done.
As we got the panels done, we fitted the first six to the fascia boards. We lifted the panels up ladders and seated them over the bottom edge of the fascia, at which point they held themselves on. I used copper 3mm x 30mm nails to fix the top fold to the bottom sarking board, checking that adjacent panels were lined up at the bottom.
We
intentionally left 1cm gaps between panels because we intended to make brackets
to cover the ends. We wanted the brackets to be distinctively different from
the panels, so the joins did not look as though had simply been done badly. I went
back to Aalco and collected three 6-metre strips on 2” x 1/8” bar. For some odd
reason aluminium bar is still sold in imperial units. The bar was surprisingly
heavy, whippy and much stronger that I would have expected. I did not take a
saw with me and could not fold the bar, so I pushed one end up one side of the
inside of the car, pulled the other end round and pushed it up the other side.
When we got home, I took them out and they sprang back to being flat straight strips.
I cut a 40cm length off and used the vice on our big workbench to hold one end whilst I tried to fold it to match the profile of the panels. It failed because I found it very difficult to fold, being so springy. When it did fold, it failed with distinctive failure lines. I gave up for a day or so and looked for (and failed to find) alternatives. So I tried again, this time going for a smooth ‘u’ shape at the bottom. After a couple of goes, I got a wide enough fold that would fit reasonably snugly over the bottom folds on the fascia panels. I measured the top 45-degree fold against the panels as I made the brackets and did these as tight as I could even though they tended to show some signs of fracturing – these would not show under the eaves trays. The brackets were for some reason much harder to coat evenly compared to the panels, possibly because the fractured areas did not charge well from the spray gun. I got them all primed, but had to give most of them two top coats. However, I got all the brackets in in one batch. The brackets were quick to install, with a single nail through a 3.5mm hole I had drilled through the top. The effect was exactly what we had hoped for and it made the fascia panels look very classy.
I pretty much straight away put the eaves protector trays on above them. The fit mostly over the sarking and under the membrane, with the short side hanging down over top tops of the panels, to carry water safely from the membrane over the edge of the roof. Whilst it did conceal the tops of the panels, the effect was really quite neat and very effective. Rain water subsequently ran onto the trays and dripped from the edges of the trays, a few mm proud of the panels. All much better that painted fascia board.
Having got a scrap of aluminium coated with primer, a couple of weeks ago, we took several leaps forwards, using one of the fascia panels for the courtyard side of the east wing. The approach is fairly low-risk: Once nailed into place, it will be a good 3m above ground level, so any minor imperfections would be hard to spot.
Preparation I drilled 3mm holes 1cm in from the top edge to let us wire the panel to our supporting frame. We got a bowl of water with washing up liquid and used a scouring pad to get loose crud off the panel. This gave it a scrubbed look in places and we got quite a bit of oxide off. We did notice a bit of pitting, otherwise a good smooth surface. Once dry, we scrubbed it down with acetone using a J-cloth. We moved the oven from our bothy/shed onto the floor immediately opposite the spray booth, so it was straightforward to gingerly lift the whole assemblage round and lower it in.
Trial & error I experimented with the compressor and spray gun set up. I set the outlet air pressure to less than one bar and used an adjuster screw on the gun to fine tune the powder flow. After a couple of fits and starts where I got clumps of powder blowing out, I managed an even flow. The electrical side of the sprayer was easy, I fixed the grounding wire via a crocodile clip to the very top of the panel, which will be out of sight. I powered up the high voltage until and used the foot control to switch it on/off. I practice it was easier and more comfortable to use the foot control in one hand than on the floor by foot.
Coating the primer So, I got going, covering the panel, 30cm x 250cm, with what I hoped was an even coat of primer. If I could see hints of aluminium below the powder coating, I re-coated it until it was an even, dull finish. I took care to get the back lip covered, that fits over the bottom of the fascia board.
Curing the primer A niggle is that the oven is barely wider than the panels, it was a challenge not to tap/scrape the bottom corners of the panel as it went in. Then it was lid on, lid closed down (with six small woodworking clamps), then switch the power on. The electronics on the oven are smart and remember the target temperature between runs, so there was nothing else to do but watch the temperature climb to 180c, around 20 minutes. The controller does seem to learn as it is used, it manged the last few degrees more quickly that the first few times and never went over-temperature by more than 0.4c. As the oven got to 180c, I started my phone timer and, after 10 minutes turned the power off, then left the oven to cool down to 80c or so before we took the lid off. As an aside, I noticed the extension lead and kettle leads got distinctly warm and I make a mental note to fully unwind the extension lead for future runs.
The result was really quite impressively good, with a couple of small patches of over-thick coating. I smoothed these down with 180 sandpaper under a small piece of wood, the recleaned it with acetone. There were a few pits that had not quite filled. I had also used slightly too-long piece of wire at one end, which meant one corner was just touching the bottom of the oven, it came out with the aluminium showing.
Prepping the top coat We broke open our 25kg back of RAL 6004 blue-green powder and put an inch or two in our second powder bottle. I used our test scrap of aluminium to practice on and was a bit disappointed at the uneven coating I got, but I went ahead and cooked it. The result was OK, the powder had melted to cover most of the imperfections. I suppose given the rough surface, I should not really have expected better.
The top coat So I got going on the primed panel. This coated better than the test piece, I put what seemed like a quite heavy coat on, until all signs of primer were obliterated and the panel had a dull but very even appearance. I put it as carefully as I could into the oven, but brushed both bottom corners on the insulation, partly wiping it off. This is clearly going to be an ongoing challenge.
So we cooked the panel and waited with some trepidation for the oven to cool down, then lifted the panel out. And lo & behold, it was good! It had a beautiful even matt-ish (slight sheen) finish,with just three imperfections: The two bottom corners were showing primer, as expected and there was a 3cm scratch on the front surface that had gone down to the aluminium. The pits all appear to have filled.
I ordered a small bottle of touch-up paint and will see if that is good enough. Otherwise we were very pleased with the finish and we both like the colour. The next steps will be to see if we can process two panels or more at a time and to finish folding the remaining panels.
We got all the trusses up on the north wing that we could, 31 in total. That leaves 8 more that will have to wait until we have the front door stonework completed. We over-ordered by two trusses, I was not certain of the length of the north wing when I ordered them.
We nailed battens across the rafters in preparation for a storm that did not really materialise, although it was breezy throughout. Next up, we trimmed the ends of the rafters, routed notches in the ends of fascia boards and nailed them up,
Over the next four working days, we got both sides of the roof covered with sarking boards. They had dried out over the winter & spring and were easy to handle.
And that is all we can do on the roof without rooflights, which we order soon. We will leave installing them until Ric gets up on 5th May.
Having decided on timber windows with powder-coated aluminium exteriors, it was not a big leap to then think about powder-coated fascia boards. We even have a RAL colour. We drew up shortlists, took the ones that we both agreed on and haggled down to – 6004 blue green. As an aside, do not look for RAL colours online. What with different rendering between devices and poor translation from RAL to RGB/CMYK, it is inconsistent & misleading. We bought a physical RAL K7 Classic colour swatch and were aghast at the difference.
We need to be able to handle chunky lengths of aluminium around 2m long. Ric has specced out a design for a) an oven that will cook them at 180c and b) a bending machine . We will start ordering stuff as soon as we get on site in April. For the oven, we need…
0.7mm aluminium sheets 1250 x 2500 to form the oven casing
100mm loft insulation to insulate the oven
strapping to hold the insulation in place
a 2kW heater and a fan, to heat the oven & spread the heat
a PID temperature controller and associated bits, to regulate the temperature
a thermometer, to go at the other end of the oven from the controller, to show when the whole oven is at temperature
a ‘D’ format kettle lead and connector
cables, screws etc. to construct the oven and wire in the electrics
fencing wire, to suspend the aluminium inside the oven as it cooks
The folding machine has a fixed part that the sheet of aluminium is held on and a moving part that pivots round 90 degrees, to bend the aluminium round a sharp angle. It is a fairly standard bit of workshop kit, but ours will be larger than average. We need…
a 2.7m length of 127x76x13 I beam (UB) for the piece that pivots up
a 2.7m length of 203x102x23 I beam (UB) for the piece that holds the sheet in place
a 2.7m length of 75x75x8mm angle to fold the sheet around
4 lengths of scaffolding tube to use as legs
weld-on hinges to attach the two lengths of I beam together i.e. to create the pivot point
bolts to hold it together
We will probably use 0.5mm aluminium sheeting for the fascia and 0.7mm for the windows. The primer and powder coating both come in handy 20kg packs – we might just get away with one of each. We will doubtless have to improvise a bit to get the whole thing working.
Whilst on aluminium sheet, we have changed our minds on heating the up-stairs areas of the steading. The building warrant expects us to use radiators, we now want under-floor heating. The only practical way to do this without using up room height is to use aluminium spreader plates under the floor boards, with 50mm PIR insulation under the plates. However, commercially-manufactured plates are not designed for using heat pumps (35c water, requiring 100mm pipe spacing) on floors with joists at 600mm centres. We reckon we can make our own, more cheaply than getting someone else to make them up for us as a ‘special’. We are not sure whether we will need a separate folding machine.
East Byreleask Steading 