firm the shape

[ronmecer]

Hi, I'm writing an instruction about "Bending PVC pipe". Here are my steps:

1. Heat the PVC pipe gently with a blowtorch.

2. Bend the PVC pipe when it becomes soft.

3. Wipe the PVC pipe with a wet rag to firm the shape.
or (Wipe the PVC pipe with a wet rag until firm/ fixed /set)

I'm not sure if "firm the shape" is a correct usage. If not, is there a better way to say it?

How about "firm / fixed / set"? Which one is more suitable in this case?

Thanks!

[BobK]

'Wipe...until set' sounds good to me. I don't think you could say 'to firm the shape' in this case, as you're doing something until it gets firm, not doing something in order to make it firm.

'Firm' can be a transitive verb, but not in this case. (A common, rather informal, use is in connection with arrangements: 'I'll phone nearer the time to firm up the details.')

b

[ronmecer]

'Wipe...until set' sounds good to me. I don't think you could say 'to firm the shape' in this case, as you're doing something until it gets firm, not doing something in order to make it firm.

'Firm' can be a transitive verb, but not in this case. (A common, rather informal, use is in connection with arrangements: 'I'll phone nearer the time to firm up the details.')

b

What's the difference between "until set" and "until firm"?
Some people say "until set" is a cooking term used in recipes.
So, why is "until set" more suitable in this case? Thanks

[Tdol]

Until set is used when a liquid hardens into a solid - jelly sets, etc - it's not only used in cooking.

[ronmecer]

Until set is used when a liquid hardens into a solid - jelly sets, etc - it's not only used in cooking.

Hmmm…Interesting. Because PVC pipe is not a liquid.

So, is it wrong to say "Wipe the PVC pipe with a wet rag until set" or "Allow the PVC pipe to cool until set"?

[SoothingDave]

Because PVC pipe is not a liquid.

You are heating it until it becomes at least semi-solid.