Lead Free Metals Casting

[flatsrat76]

I have searched this forum on lead free castings but did not see anybody that is casting with 99% tin http://www.rotometals.com/product-p/tinhighgradeingot.htm

Besides price what are some other pros and cons of alternative metals? Any info would be great

Flatsrat76

[pirkfan]

I don't use ingot tin, but I do cast quite a bit with lead free tin solder. If you get lucky, you can beat the price of the Rotometals on Ebay for solder which is 97/3 or 95/5, depending on whether it is a tin/silver or a tin/copper alloy. For example, right now there is a "buy it now" offer for 10 lbs of lead free Oatey solder for $85 with free shipping ($8.50/lb)

Pros: Melts at a temp lower than lead and fills details in molds very well (tin expands slightly when changing state from liquid to solid). If you don't want to paint the lure, solder doesn't corrode and stays a shiny white silver. Weighs about 70% of lead for the same size lure, so a one lb roll of solder casts more lures of equal size (not weight) than 1 lb of lead. Lead free solder avoids the problem of "tin pest" which occurs with pure tin at low (below 56 degrees fahrenheit) temperatures, because the silver or copper alloyed in the solder stabilizes the alloy. The lighter tin alloy offers a different action to lures such as slab spoons. Non toxic.

Cons: Number 1 of course is Cost. I haven't tried Tin in bottom pour pots, because I think it might be wise to remove all tin from the pot before it solidifies (expands when it changes state which might not be good for the pot), so I use it only in a Hot Pot II. I also recall (but can't document this) that I read somewhere that tin reacts with steel at high temp and might corrode steel pots. I also have some problems with voids in long thin lures which may be related to being unable to get either the tin, the mold, or the inserts hot enough during the pour. Tin is not very malleable and would not work well for sinkers such as split shot.

I have searched this forum on lead free castings but did not see anybody that is casting with 99% tin http://www.rotometals.com/product-p/tinhighgradeingot.htm

Besides price what are some other pros and cons of alternative metals? Any info would be great

Flatsrat76

[flatsrat76]

Pirkfan

Great reply, I never have heard about Tin Pest

looks nasty.

I also looked up Tin pest on the wikipedia website and at the end of the contents it said, Tin pest can be avoided by alloying with small amounts of electropositive metals soluble in Tin's solid phase e.g. Antimony or Bismuth, which prevent the decomposition. Silver, Indium, and Lead have also been used, but Lead is not soluble in Tin's solid phase.

I was thinking that the ALLOY-R-92-PEWTER Casting Ingot 92% Tin, 8% Antimony would eliminate Tin pest. What do you think?

Thanks again for responding

Flatsrat76

I don't use ingot tin, but I do cast quite a bit with lead free tin solder. If you get lucky, you can beat the price of the Rotometals on Ebay for solder which is 97/3 or 95/5, depending on whether it is a tin/silver or a tin/copper alloy. For example, right now there is a "buy it now" offer for 10 lbs of lead free Oatey solder for $85 with free shipping ($8.50/lb)

Pros: Melts at a temp lower than lead and fills details in molds very well (tin expands slightly when changing state from liquid to solid). If you don't want to paint the lure, solder doesn't corrode and stays a shiny white silver. Weighs about 70% of lead for the same size lure, so a one lb roll of solder casts more lures of equal size (not weight) than 1 lb of lead. Lead free solder avoids the problem of "tin pest" which occurs with pure tin at low (below 56 degrees fahrenheit) temperatures, because the silver or copper alloyed in the solder stabilizes the alloy. The lighter tin alloy offers a different action to lures such as slab spoons. Non toxic.

Cons: Number 1 of course is Cost. I haven't tried Tin in bottom pour pots, because I think it might be wise to remove all tin from the pot before it solidifies (expands when it changes state which might not be good for the pot), so I use it only in a Hot Pot II. I also recall (but can't document this) that I read somewhere that tin reacts with steel at high temp and might corrode steel pots. I also have some problems with voids in long thin lures which may be related to being unable to get either the tin, the mold, or the inserts hot enough during the pour. Tin is not very malleable and would not work well for sinkers such as split shot.

[pirkfan]

Pewter would probably be fine, obviously it's a stable alloy. I've even heard of people buying junk pewter to use for molding. (I believe some old pewter actually used lead as a component, however).

Pirkfan

Great reply, I never have heard about Tin Pest

looks nasty.

I also looked up Tin pest on the wikipedia website and at the end of the contents it said, Tin pest can be avoided by alloying with small amounts of electropositive metals soluble in Tin's solid phase e.g. Antimony or Bismuth, which prevent the decomposition. Silver, Indium, and Lead have also been used, but Lead is not soluble in Tin's solid phase.

I was thinking that the ALLOY-R-92-PEWTER Casting Ingot 92% Tin, 8% Antimony would eliminate Tin pest. What do you think?

Thanks again for responding

Flatsrat76

[flatsrat76]

Pewter would probably be fine, obviously it's a stable alloy. I've even heard of people buying junk pewter to use for molding. (I believe some old pewter actually used lead as a component, however).

pirkfan

I also think the pewter would work well in the cooler months.

I would like to thank you again for helping me out , saved me some time and $$$

Flatsrat76

[Fatman]

Flat

Ebay sometimes has listings from Hallmark Metals Corp

930 Wellington Avenue

Cranston, RI 02910

Casting Metal Pewter Alloy with silver 6+ pound bars

Well I wanted to know if they had one that was cheaper with no silver in it, and other questions

do you offer the 92-8 at a cheaper price as there's no silver in it??? $59.00

Does it come in the same 6+ lb bar??? Yes

Also what does 6+ mean?? 6 1/2 lbs. Avg 6.6 lbs per bar

In laymans terms how close is this to the weight of pure lead?? Lead 0.4090 lbs.cu.in -- 0.2624 lbs.cu.in (Hey I'm not a metalurist I don't know this stuff)

Do you provide the MSDS sheet showing all elements??? Yes

This is just one company I checked with and it's about 2/3 of the weight of lead, With a pound of this material I can make approx. 200-250 per lb. (if I'm wrong correct me) of 1/16th oz jigs. That's still alot , although I'd then have to bring up the question, can you powder paint them the same way, as this stuff melts at a lower temp.

I've posted about the lead free materials before as Vermont has lead laws (right now it doesn't affect jigs), but states next to me have different laws.

Fatman

[Ogajiga]

I've heard about tin rot when cold, but never experienced it. Pure tin is soft so I add a little bismuth to tin to strengthen some castings, but other metals alloyed with tin seem to negatively affect pourability. Unless one prefers lightest possible weight, bismuth might be a better lead substitute choice.

Pure bismuth PROS: melting point 520*= powder paintable, 85% lead weight, non-toxic.

Pure bismuth CONS: brittle spike barb collars are fragile, cost $13-$15 per lb.

Tin can be alloyed with bismuth in any amount, generally the pros & cons will be proportionate to amount added.

Adding tin PROs: toughness, shinier finish, improved pourability.

Adding tin CONS: lowered weight, reduced melting points hazardous for powder painting.

Altho bismuth(Bi) & tin(Sn) can probably be alloyed & cast in any proportion, I presently mostly use alloys Bi5 Sn95, Bi58 Sn42, Bi67 Sn33, Bi87.5 Sn12.5. I might try alloying 1% bismuth into my pure tin castings to mitigate tin rot.

[flatsrat76]

Fatman

I will check them out on ebay.

On rotometals website they state that 99.9% lead is .4092 lbs.cu.in and 99.9% Tin is .2633 lbs.cu.in and I did the math and Tin is 35.65 % lighter then lead ............... .4092 - 35.65% = .2633

Flatsrat76

Flat

Ebay sometimes has listings from Hallmark Metals Corp

930 Wellington Avenue

Cranston, RI 02910

Casting Metal Pewter Alloy with silver 6+ pound bars

Well I wanted to know if they had one that was cheaper with no silver in it, and other questions

do you offer the 92-8 at a cheaper price as there's no silver in it??? $59.00

Does it come in the same 6+ lb bar??? Yes

Also what does 6+ mean?? 6 1/2 lbs. Avg 6.6 lbs per bar

In laymans terms how close is this to the weight of pure lead?? Lead 0.4090 lbs.cu.in -- 0.2624 lbs.cu.in (Hey I'm not a metalurist I don't know this stuff)

Do you provide the MSDS sheet showing all elements??? Yes

This is just one company I checked with and it's about 2/3 of the weight of lead, With a pound of this material I can make approx. 200-250 per lb. (if I'm wrong correct me) of 1/16th oz jigs. That's still alot , although I'd then have to bring up the question, can you powder paint them the same way, as this stuff melts at a lower temp.

I've posted about the lead free materials before as Vermont has lead laws (right now it doesn't affect jigs), but states next to me have different laws.

Fatman

[flatsrat76]

I forgot to add on my last post

I see that 99.9% Tin melts at 450°f , R92 melts at or about 466° F, But it has 8% Antimony in it and Antimony melts at 1166°F, wouldn't it make the melting point more then 16°f + - ? then 99.9% Tin?

Flatsrat76

[Ogajiga]

Casting alloy melting points don't seem to be predictably proportional to the melting points of their separate metals. For example an alloy of 58% Bismuth(520*F) and 42% tin(450*F) is 281*F.

[flatsrat76]

Hawnjigs

I don't get it, But I have seen Bismuth/Tin blends that melt low

Flatsrat76

Casting alloy melting points don't seem to be predictably proportional to the melting points of their separate metals. For example an alloy of 58% Bismuth(520*F) and 42% tin(450*F) is 281*F.

[Fatman]

Flat

I was lost on the melt temps of the different mix's until Hawn explained it to me too!!!! LOL This is why I love this site!!! Been melting and molding since I was 11 and I had NEVER fluxed my material. Read the what was at the time a thread on fluxing and tried it, worked great although the first time it flamed up I thought Oh Crap trouble!!! but it really does work!!! and makes your materials mold oh so much better.

I'm still asking questions about this thing we call molding and loving it.

Fatman

[flatsrat76]

Fatman

I am lost about that, Maybe Hawn can explain it on this post =)

I also never flux, do you use the beeswax?

Flat

I was lost on the melt temps of the different mix's until Hawn explained it to me too!!!! LOL This is why I love this site!!! Been melting and molding since I was 11 and I had NEVER fluxed my material. Read the what was at the time a thread on fluxing and tried it, worked great although the first time it flamed up I thought Oh Crap trouble!!! but it really does work!!! and makes your materials mold oh so much better.

I'm still asking questions about this thing we call molding and loving it.

Fatman

[Ogajiga]

Fatman

I am lost about that, Maybe Hawn can explain it on this post =)

I also never flux, do you use the beeswax?

Most of the technical details about metals casting are provided by our premier resident metalurgist, "sagacious". To my memory, the subject of unpredictable alloy melt temps is unaddressed so I'm in the same boat not understanding why but helps to know.

[pirkfan]

One issue with low temperature melting alloys, the inserts have to be relatively hot, because these alloys also return to a solid state at low temperatures. If a tin alloy hits a cold wire insert, it frequently causes a void, even if the mold itself is hot. I have heated inserts in the mold with a small butane torch, then immediately closed the mold and cast the item. Because the aluminum mold dissapates heat so effectively, you can actually heat stainless inserts, even to red heat, without mold damage, and the alloy pours with much less chance of a void.

quote name='hawnjigs' date='25 December 2009 - 08:22 PM' timestamp='1261790556' post='136852']

Most of the technical details about metals casting are provided by our premier resident metalurgist, "sagacious". To my memory, the subject of unpredictable alloy melt temps is unaddressed so I'm in the same boat not understanding why but helps to know.

[Ogajiga]

Quote: "Tin is not very malleable and would not work well for sinkers such as split shot."

This is true for tin alloys (like 97-3 solders) since other metals added noticeably hardens tin. PURE tin makes malleable split shot similar to soft lead - Dinsmore in particular makes EZ to close & open tin split shot.

I too have experienced the tendency of tin & its alloys to void around inserts including hooks. Heavy wire hooks often require pre-heating, & while heating small light hooks isn't always necessary, they will often cast a bit loose in tin jig heads especially no collar types.

[flatsrat76]

One issue with low temperature melting alloys, the inserts have to be relatively hot, because these alloys also return to a solid state at low temperatures. If a tin alloy hits a cold wire insert, it frequently causes a void, even if the mold itself is hot. I have heated inserts in the mold with a small butane torch, then immediately closed the mold and cast the item. Because the aluminum mold dissapates heat so effectively, you can actually heat stainless inserts, even to red heat, without mold damage, and the alloy pours with much less chance of a void.

quote name='hawnjigs' date='25 December 2009 - 08:22 PM' timestamp='1261790556' post='136852']

Most of the technical details about metals casting are provided by our premier resident metalurgist, "sagacious". To my memory, the subject of unpredictable alloy melt temps is unaddressed so I'm in the same boat not understanding why but helps to know.

Never would of thought of a lower temp tin not molding good with a cold hook..... Good stuff

Flatsrat76

[sagacious]

I forgot to add on my last post

I see that 99.9% Tin melts at 450°f ' date=' R92 melts at or about 466° F, But it has 8% Antimony in it and Antimony melts at 1166°F, wouldn't it make the melting point more then 16°f + - ? then 99.9% Tin? [/quote']

Casting alloy melting points don't seem to be predictably proportional to the melting points of their separate metals. For example an alloy of 58% Bismuth(520*F) and 42% tin(450*F) is 281*F.

Hawnjigs is correct that the alloy melting point is not usually proportional. Unfortunately, prediction of the melting point of alloys is not as straightforward as one might hope.

It's not really a "melting-point" addition/subtraction situation. It's the chemical and thermodynamic properties of the mixture that determine the melting point. Sadly, one cannot just say, OK, it's 90% tin and 10% bismuth, so the melting point must equal to 90% of tin's melting point plus 10% of bismuth's melting point. Doesn't work that way with most metals.

Why is the melting point of the alloy lower than one might otherwise suspect? Many metal combinations (alloys) that are even slightly miscible (mixable) have a eutectic point. The eutectic point is that exact ratio of the component metals that gives the lowest melting point.

If there is a eutectic point, then there's a point where adding some of the higher melting point metal actually reduces the melting point of the lower melting-point metal. So, adding a tiny amount of copper to tin will actually drop the melting point to below that of pure tin.

Here's an everyday example of how a mixture may have a lowered melting point. Consider that the melting/freezing point of water is 32*F. Consider also that the melting point of salt is way high. But mix salt into water and the melting/freezing point plummets to something like -6*F. Salt and water actually have a eutectic point, which is about 25% salt and 75% water. The same sort of thing commonly happens when metals are mixed, and results in a melting/freezing point lower than one might predict.

Hope this sheds a little light on it. Regards, and good luck.

[Vodkaman]

Great explanation Sagacious, especially the salt/water example.

Dave