| dead easy mate!! with sprue heat it till it starts to bend then in one continuous pull stretch it out. here is the best bit though, once you have fixed it in place (i use superglue or if very fine a blob of varnish) you just need a soldering iron when it has reached temp just hold it close to the sagging sprue and like magic it will tighten up!! if you havent got a soldering iron just heat up a screwdriver or needle whatever the size you require to get access (Please bare in mind that the item should be almost red hot for this to work) Another method is to use fishing line as this comes in different thicknesses this needs to be tensione as you glue so superglue is really then only answer for this, but if you put a dab of accelerator on the joins it is dead easy and very quick.
hope this helps |