Author Topic: Using Colphos 90 for boiler fittings (Read 1075 times)

AVTUR · « **on:** April 21, 2025, 05:40:03 PM »

I intend to make some boiler fittings using Colphos 90. These will be fabricated using silver solder. The boiler is for an LBSC Speedy loco.

Some tell me that the lead in Colphos 90 will effect the integrity of the solder. Is this true and has anyone got any experience of this?

AVTUR

crueby · « **Reply #1 on:** April 21, 2025, 06:21:28 PM »

Only slightly more lead than 360 brass, which takes silver solder great. Thats all I know, never used Colphos 90.

baz · « **Reply #2 on:** April 21, 2025, 09:59:57 PM »

I have made quite a few bushes out of Colphos 90 and never had any problems silver soldering them or any problems with them afterwards. Sorry I can’t give a technical / scientific answer, only that it works fine for me.

Charles Lamont · « **Reply #3 on:** April 22, 2025, 02:39:13 PM »

I would be a bit concerned about the lead content, but my worry might be unfounded. Even if someone convinced me it was OK I think I would still opt for PB102 in preference. What does your boiler inspector say?

Jasonb · « **Reply #4 on:** April 22, 2025, 03:09:49 PM »

I know the likes of Western Steam use SA660 in their boilers and that has a 7% lead content which is a lot more than the 4% in Colphos

AVTUR · « **Reply #5 on:** April 22, 2025, 05:58:13 PM »

Thanks all.

The boiler has been made by Western Steam. I am considering the fittings and trying to avoid brass due to possible de-zincing problems. Looking at other sources and taking into account comments made here I am about to buy metal. I shall have a chat with one of our boiler inspectors within the next three weeks.

AVTUR

Charles Lamont · « **Reply #6 on:** April 22, 2025, 08:56:04 PM »

I read in haste and replied thinking about the mounting bushes in the boiler rather than the fittings themselves. With these I would be much less concerned.

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