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A wooden box in 12 mm multiplex

10 mm isolation glue in the wooden box.

Because I messured tempertures of 103 °C in winter time, I changed from polystyrene "easy-mo" to polyeruthane. Polystyrene is melting already between 95 en 105°C!

Problem with polyeruthane is the 3 cm tickness, I can't find it thinner. I had to cut it with an electrical heating wire. The electrical heating wire from a hair dryer was perfect to cut the isolation in 10 mm tickness.

Aluminium plates placed arround the wooden box for protection.
An aluminium plate of 10.5 cm folded at 10 mm, 12 mm, 70 mm and 12 mm.

I have glued the aluminium sheet on the isolation and I used the same glue to hang paper on the walls.

The aluminium profile cuted at 45° and soldered with aluminium alloy.

With a little bit of exercise it wil work. Soldering aluminium is not common but it really works.

The inner site of the aluminium profile.

For the collector, 50 m soft copper tube of 8 mm. I lengtened the 50 m copper tube, the sewer pits were just 25 m from eat other so I used them fot that.

8 tubes of 8 mm welded in the haed collector of 22 mm.

The collector is placed verticale so welding is mutch more easy. The left and wright tubes are for justifying wile welding.

To drill the holes I made a form in wood. So all the holes are exact on the same distance.

Completing the collector.

The result with autogenous welding

The aluminium plates placed on the copper tubes and not yet painted. To avoid galvanic corrosion I put some heat sink compound (Dow Corning) between the pipes and the alu-plates. So it wasn't really for the better heat transfere.

After a long time searching I found a plastic bark witch was able, after modification, to fit as a socket.

One collector is made in 12 mm multiplex wood, water resistant, with 10 mm insulation. The outside is covered with an aluminium plate of 0.6 mm. Glass of 4 mm tickness. The complete weight is 28.9 kg, what is really heavy!

The second is made with 12 mm multiplex wood and the back of 4 mm triplex. Also covered with 0.6 aluminium at the outside and 6 mm polycarbonate glass. Weight is 12.7 kg, what is very nice!

To hold the glass (in the aluminium frame) on the case I maded some clamps in aluminium. Very cheap and you don't need screws.

No srews so no risk of laeks.

With 6 clamps the box of 12.7 kg becomes very robust. With no other aleternative I keep this idee.

Copper plates.

The next 4 collectors:
Because the heat transfer of copper is twice of aluminium and the risk of corrosion between aluminium and cuppe I decided to use copper as collector plate. I took the same thickness for cupper as aluminium, this was a little mistake because the copper is more heavier and stiff then the aluminium of 0.6 mm! I think copper plates of 0.4 would be nicer.

The cutting was more heavyer

Pressing the groove in the copper plates was also more difficult. The press machine was going to his max limits. The copper plates for a collector of 1.5 m2 weight 8 kg witch is very heavy!

I made the copper plates shorter, so 4 plates are going on 1 tube, by doing this, pressing the groove in to the shorter plates was mutch easier.

All the 4 collectors of 1 m wide on 1.45 m high, front and back, are painted in a white primer (it is a primer for nonfero).

Then the front is painted in black, the coating is the same as on a black school board.

Now the paint can dry in the sun.