Increasing Lure/Mold Size

[GMan]

Larry (or others),
Have you had success increasing a lure/mold size by soaking over night in mineral spirits with TWO PART molds? I'm concerned that if both halves do not expand exactly the same they will not matchup as well. Any confirmations, pointers, tips, or negatives? Thanks.

[GMan]

So I tried it experimentally with a two peice muskie size crank bait mold I designed with the lip part of the mold to be poured in, rather than added separately afterwards. I submerged it in mineral spirits overnight. It expanded alright, I'd say a good 10%. The top half of the mold warped a bit at the outside, but I think that can be overcome by clamping the mold together between two peices of plexiglass or similar (which I alays do). I'm not sure if the lure edges line up well, yet, but the problem is the slot area for the lip expanded/warped in on the slot closing the lip area; I can pull it back to the right size, but I cannot keep it that way when I put the mold halves together for pouring. (I'd attach picture to show, but I don't know how to do that.) Anyway, if you are thinking about enlargening a two peice mold by soaking in mineral spirits, you may want to think again and try something else. I'm not saying it can not be done; it would defineitly take more precautions, attention, and work than I employed though.

[aka anglinarcher]

Thanks for the info.

You can get a free acount on Photobucket, then load your pictures on it. You then copy the link to this forum so we can see the pics.

For example: http://s1151.photobucket.com/albums/o62 ... 20Dragger/

Larry told us in the following thread as well. viewtopic.php?f=9&t=13085

Hope this helps.

[Mike - Alumilite]

Two piece molds can be a little less consistant because there are more variables. I typically don't leave it in overnight as I like to keep an eye on it. So I typically start it in the morning and monitor it. The reason two piece molds become tough is that thinner areas expand faster and thicker areas take longer forming some warpage. If the two halves of the mold are the same size and thickness, they typically expand at the same rate and can be clamped together well enough to get a decent part out which can then be touched up with some sand paper if needed before making the mold of the bigger master.

Mike

[GMan]

So I left my experimental mold (referenced above) out on the work bench for a couple weeks...it has shrunk back to original size! Am I missing something?

[aka anglinarcher]

Nope, that is normal.