walleye warrior

Custom Aluminum mold question

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I bought 2 custom made jig molds from a local company in here in michigan. So my question is, are there different grades of aluminum used for making molds. I notice a difference in the amount of heat these new molds hold compared to my do-it molds and a Shawn Collins molds I have.

The new molds are a darker grey color kind of similar to do-its. With all that being said they are great molds and produce a very nice jig, but I do have a concern that they could warp holding all that heat. Any thoughts or input?

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We machine a lot of aluminum where I work. We found that 6061 T6 is a very good aluminum to use along with great machine-ability.  T6 is the temper, and it is very hard. I don't know what Shawn Collins uses, but I'm going to bet he uses 6061 T6.  Do-Its standard molds are sand cast, I do not know what their alloy is. I have never had an aluminum piece of block warp. If it gets hot enough it will expand, as I've seen that in Do-It molds, but it didn't have any effect on the pouring or finished product.

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I've had several molds for soft plastics  from different manufacturers distort from excessive heat by shooting them  over & over.When this happens i usually just shoot some other molds until the others cool off & then you're good to go again for a while.Lead molds are no different according to my buddy that pours a lot of lead.  Just the nature of the beast i guess when fooling with aluminium & excessive heat.

Edited by Les Young
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I use primarily 6061-T6 or 6061-T6511, because its the most economical aluminum that machines fairly well.  5052 is similar in price, but doesn't machine as well.  7075 machines "BETTER," but it costs a lot more.  Those are all wrought alloys usually.  6061 doesn't cast with conventional methods worth a darn.  I don't think 5052 or 7075 do either.  There are also cast alloys that machine will.  Those are great for plants that are setup to recycle.  I can't speak to cost.  

I think 6061 is lower cost due to high production, because it is formable, machinable, and weldable.   

5052 is also low cost due to higher production, because its formable, modestly machinable, very weldable, and much more corrosion resistant.  Its probably one of the most popular "marine" alloys. 

7075 is generally not considered weldable (except with very specialized methods), but it is highly corrosion resistant and very strong.  Stronger than some steels. 

Wrought alloys will have some internal stresses due to their forming method.  Cast alloys likely will be more homogeneous due to their forming method.  I can very much see 6061 distorting when heated. 

Anyway, its quite likely that the OPs mold was made from Fortal or Mic-6 or some other machinable alloy the shop had on hand.   I am sure different aluminum alloys will transfer heat at different rates just like other properties may differ. 

 

 

 

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