The smoke box door would be simply pushed in to the smoke box. So this should have proper tightness. I made the part that fitted in the smoke box from 1.6mm copper disk and 5X1.6mm copper strip. The copper disk was cut out by trepanning. The disk and strip were silver soldered together.

煙室扉は煙室に押し込みとなるので程よい硬さで煙室に嵌らなければなりません。煙室に嵌る部分は1.6mmの銅板をトレパニングで切り出し。1.5X5mmの銅帯を銀ロウ付けすることにしました。円盤に帯板を巻きつけ、SUSの針金で縛ります。

Parts were soldered.

銀ロウ付け完了。

After pickling the out side were turned to get nice fitting to the smoke box.

酸洗後、周囲を切削し、煙室に少し固めに嵌るようにします。

Good fitting!

いい感じで嵌ります。

Outside part of the smoke box door was made from 1mm brass plate. I made the diameter of this slightly larger than the smoke box to have some hold when it removed.

外板は1mmの真鍮板。外すときに爪がかかりやすいように外径より少し大きく切削しました。

Back side of the door.

内側はこんな感じ。

For dummy door, I needed 5mm brass plate, but did not have it. So I silver soldered two disks of 3.2mm brass plate.

ダミーのドアは5mm厚が必要なんですが、手持ちになかったので3.2mmの真鍮板を二枚張り合わせることにしました。一枚には銀ロウが流れる隙間を確保するためにポンチを打っておきました。

After soldering I tapped the centre hole with M8 fine pitch and screwed on a mandrel to turn it.

銀ロウ付け後真ん中の穴にM8細目のタップを立て、ヤトイにねじ込みます。

I turned down the thickness to 5mm and cleaned up outside.

厚さを5mmに切削し。外径を合わせ。

Rough cutting.

荒削り。

Curved surface was cut by a scraper. The scriber worked quite well with this angle (30 to 45 deg). This angle was totally out of my imagination. If the scribe applied in right angle, it did not work well.

キサゲで曲面を削ります。キサゲはこんな角度(30°から45°）が一番良く削れます。全く想像していた角度と違うなー。直角に当てたんじゃよく削れないんですね。

The scraper was made from an old file. The angle of the edge was like this. I did not know this angle was correct or not, but it worked well.

キサゲは古やすりを研いで作りました。刃先の角度はこんな感じ。いいかどうか分かりませんがよく削れます。

I scraped the surface checking with a curve gauge.

ゲージで確認しながら削りました。

Failure

The silver solder did not flow well leaving some voids. They came out on scraping. I could not use it and would do this again after getting thicker brass.

失敗

銀ロウが完全に隙間を埋めてなくて削ると隙間ができてしまいました。失敗です。これでは使い物にならないな。5mmぐらいの真鍮板を入手後、やり直します。