Green Stuff, Heat & Expansion

[residentalien]

I\'ve been reading up on the GS articles here and the general opinion here is that it expands bubbles on the application of heat. NOw Does that hold true even AFTEr it has cured or only during the curing process.

I ask because I tend to use a hairdryer to speed up paint dry up times and I\'d hate to have \"Strange growths\" under my paint work !

 

[minimaker]

It\'s correct, though I\'m not sure what temperature and exposure is needed for this. It is something that you sometimes see when mouldmaking. If there are any airbubbles these can expand and deform the figure on that spot. It\'s a temporary effect but will nevertheless mess up the cavity. This is why care needs to be taken when making figures for production to keep all airbubbles out.

 

[residentalien]

Originally posted by minimaker
It\'s correct, though I\'m not sure what temperature and exposure is needed for this. It is something that you sometimes see when mouldmaking. If there are any airbubbles these can expand and deform the figure on that spot. It\'s a temporary effect but will nevertheless mess up the cavity. This is why care needs to be taken when making figures for production to keep all airbubbles out.

I\'m sorry , but to be clear....are you saying the expansion-by-heat application can happen anytime mea ning even after it has cure d?

 

[Dragon Forge Design]

In sculpting with GS it is common to speed up the curing time to put it in a little \"cooker\" or oven made from a large coffee can and a lightbulb of low wattage. Nothing to warm. I use a 40W bulb. This speeds up the drying /curing time.

When using heat to cure epoxy, yes air bubbles can expand because as the air heats up it expands. Once cured there should be no problem. If it to be vulcanized the air bubbles will collapse leavig a small dip or hollow spot.

If you are just using GS for conversions and letting it air dry.. using a hair dryer to speed dry paint should have no effect on the putty or any air bubbles below the surface..you wont get enough heat from the hair dryer and would scorch the paint befor effecting the putty..

One note on using GS to convert models that are plastic or have plastic parts..especially GW plastics. The heat from a lightbulf can cause melting or warpage in GW plastics. Its best to let air dry.

The key it to keep air bubbles out of your GS

 

[residentalien]

^^ thank you

thats the info I was looking for !

 

[Klute]

Ive got a nice little needle tool just for \"popping\" trapped air.

 

[darkeye]

greenstuff expansion

you can happily heat or even bake g,s just not too hot, max of 100*.
in a moulding machine the g.s gets so hot it turns brown/black.
it will \'bubble \' up if it has previously retain moisture or trapped grease, so keep your hand clean folks!! ==timo

 

[Dragon Forge Design]

Originally posted by Klute
Ive got a nice little needle tool just for \"popping\" trapped air.

That will work. Sometime when Im working something and I notice a bubble that I can\'t get to go away..Ill leave it alone and let it cure..then co back and dig it out and patch the spot with new GS.

The key is when mixing the putty be careful not to trap air in it when your mixing it.