Boiler questions

[Mark Boothman 1Participant @markboothman1]

Hi all

I'm looking for some advise on drilling a 2" scale Minnie boiler. I'm ready for drilling the copper boiler to fit the cylinder. Do I drill all the way through in to the boiler or do I need to not go through all the way. I'm sort of wondering if steam might come through the threads? Also is it advised to use bolts or is it ok with studs and nuts? If I use studs are they ok out of stainless? Are there any specific/recommend drill bits to drill the copper as I've drilled a test hole for the steam chest and had a bit of a job. Almost like the drill bits are to sharp and rip there way in. Thanks in advance for the info/advise.

[Mark Boothman 1Participant @markboothman1]

Drilling

[JasonBModerator @jasonb]

usually drilled right through, use a thread sealant on assembly. assume you have the thickening pad inside the boiler.

Quite a lot of people solder nuts onto lengths of studding to make "bolts" that look like nuts and studs but easier to undo if the need arises.

Bronze studs would be best

If you can do the drilling on a mill then lock the quill and lower the head or raise the table as this tends to resist any pull from the bit. Others stone the cutting edges to reduce the rake or you can buy slow helix drills for grabby materials

[Mark Boothman 1Participant @markboothman1]

Hi Jasonb

Ok thank you for the help. Yes it has got the pad inside. Hopefully it will be in the right place as I purchased it second hand.

When you say sealant. Do you mean a thread lock or stud lock type of stuff or can I use ptfe tape?

I know you say bronze studs are best. Dose the mean that stainless steel ones are not recommend?

I Have a Bridgeport, so I will try the knee to start with and take it from there.

Thanks again.

[Harry WilkesParticipant @harrywilkes58467]

Been some year since I did my 3" and I used Rocol foliac paste but I'm sure there will be other suggestions and if I remember stainless is not recommended

H

[JasonBModerator @jasonb]

Yes Foliac is quite a common one for the boiler to cylinder joint as well as some on the studs. Don't use a locking type as you may need to get the studs out of the soft copper at some time. There are liquid sealers by Loctite and others made for pipe joints etc often a form of liquid PTFE. Though I would not want to use tape for this job.

Stainless or Bronze stud/bolts is a bit of a grey area at the end of the day best to check with whoever will be testing the boiler to see if they will be happy with stainless.

[Mark Boothman 1Participant @markboothman1]

Thank you jasonb and h.

When using bronze for the studs is it LG2, PB1 or PB102 grade or something else?

I noticed that jason said to use foliac between the cyclinder and boiler. Is that the same for everything that bolts/fixes to the cylinder, and would i use a gasket with foliac or not.

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