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philB

Resin Casting Advise Required Please

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Hi all

Having made wooden baits for a good while now I am going to branch out into resin cast baits. I have done a lot of investigation into resin casting and I am confident of success (hopefully rolleyes.gif). I have my cast box made and materials on order RTV silicone, polyester resin, microbubbles, plasticine and finally mold release (I know this is not really needed but wont do any harm) I also have the master bait from which the cast will be made. The finished baits will be through wired so a wire harness will be incorporated at the casting stage, so I reckon I am just about ready to go.

A couple of things still elude me though.

First, I do not know if it is possible to actually make resin float with microbubbles ? it seems a tall order to me as a novice, should some further buoyancy facility be made for example attaching say a couple of small cork balls to the wire harness which could be done very simply.

Second, how do I know how much filler (microbubbles) to add ?.

Third, do microbubbles float to the surface of the resin or do they remain suspended, if they do float this would not be an issue as the filler and vent will be on the top of the bait anyway, I am just curious.

Fourth, do I have to recess the mold for the wire harness eyes or will I be able to just lay the harness eyes onto the surface of the mold, what I am asking here is will the silicone mold itself around the eyes when the 2 halves are clamped together or will I get unacceptable amounts of leakage of resin around the eyes ?

Thanks in advance

philB

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PhilB,

It seems to me that you have done your research and have some specific questions, unlike many.

#1 Yes it is easy to get resin to float with microbubbles alone.

#2 Try to start with 50% MB's in each measure of part A and part B of resin, adjust accordingly.

#3 MB's do tend to suspend in the resin, but be sure to mix both parts before mixing together.

#4 It would be my advice to mold in line tie and hook hanger attachments in your two part mold.

Good luck and have fun,

Douglas

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PhilB,

It seems to me that you have done your research and have some specific questions, unlike many.

#1 Yes it is easy to get resin to float with microbubbles alone.

#2 Try to start with 50% MB's in each measure of part A and part B of resin, adjust accordingly.

#3 MB's do tend to suspend in the resin, but be sure to mix both parts before mixing together.

#4 It would be my advice to mold in line tie and hook hanger attachments in your two part mold.

Good luck and have fun,

Douglas

Thanks Douglas. Excellent advise, just what I needed. "Have fun", that's assured wink.gif.

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Hey Phil, Coley here. I cast 80% of my baits.

What resin are you using? As hard as I tried

I was never able to have any luck with foam

castings. All my baits are cast from RC-3

from Alumilite. This is a Urethane Resin.

You will need a good scale to get it right.

I pour 3.5 oz of part A (by weight) into a 9 oz cup

I pour 3.5 oz of part B (by weight) into separate a 9 oz cup.

I add 3 1/2 Tablespoons of Micro balloons to

each cup.

Mix both well and keep mixed well during the process.

I then add .300 oz of each part to a 3 oz cup.

Mix well and pour slowly into mold. Pour in a very

thin stream or resin may clog pour hole before you finish.

Dust your mold with baby powder or similar and

bang molds against each other to remove excess powder.

Check TU for a live feed from Clinton on Sat, May 1st,

I may be doing this on the feed.

Good luck.

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Hey Coley I will be watching with interest too. Have fun . Pete

Hey Phil, Coley here. I cast 80% of my baits.

What resin are you using? As hard as I tried

I was never able to have any luck with foam

castings. All my baits are cast from RC-3

from Alumilite. This is a Urethane Resin.

You will need a good scale to get it right.

I pour 3.5 oz of part A (by weight) into a 9 oz cup

I pour 3.5 oz of part B (by weight) into separate a 9 oz cup.

I add 3 1/2 Tablespoons of Micro balloons to

each cup.

Mix both well and keep mixed well during the process.

I then add .300 oz of each part to a 3 oz cup.

Mix well and pour slowly into mold. Pour in a very

thin stream or resin may clog pour hole before you finish.

Dust your mold with baby powder or similar and

bang molds against each other to remove excess powder.

Check TU for a live feed from Clinton on Sat, May 1st,

I may be doing this on the feed.

Good luck.

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[

Mix both well and keep mixed well during the process.

I then add .300 oz of each part to a 3 oz cup.

Mix well and pour slowly into mold. Pour in a very

thin stream or resin may clog pour hole before you finish.

Dust your mold with baby powder or similar and

bang molds against each other to remove excess powder.

Coley,

Am I assuming correctly that you mix a larger batch for multiple baits? You mention mixing .300 oz. of each part in the smaller cup, is this the amount you are using for one bait. If not how big is the bait you are pouring that you need that large a volume of resin. Just trying to compare bait size. I use a total of 2 oz. of resin and 1.75 TBS of microballoons for a seven inch bait.

When and why are you dusting the molds with the baby powder, never heard that one before. You can always learn something new.

Thanks,

DaveB.

KelpKritter

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[

Mix both well and keep mixed well during the process.

I then add .300 oz of each part to a 3 oz cup.

Mix well and pour slowly into mold. Pour in a very

thin stream or resin may clog pour hole before you finish.

Dust your mold with baby powder or similar and

bang molds against each other to remove excess powder.

Coley,

Am I assuming correctly that you mix a larger batch for multiple baits? You mention mixing .300 oz. of each part in the smaller cup, is this the amount you are using for one bait. If not how big is the bait you are pouring that you need that large a volume of resin. Just trying to compare bait size. I use a total of 2 oz. of resin and 1.75 TBS of microballoons for a seven inch bait.

When and why are you dusting the molds with the baby powder, never heard that one before. You can always learn something new.

Thanks,

DaveB.

KelpKritter

Actually the amount I use on my baits varies. Some take .235 oz of each and some

take more. I have poured enough to get it about right with no waste. I only pour one bait with each mix in the smaller cup, reason being, I mix the resins together until

the cup starts to get warm.

About the powder. I use some off brand baby powder. The powder does three things it fills in any small pin holes in the casting, allows the resin to flow freely through

the mold and makes the casting very, very smooth.

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Hey Phil, Coley here. I cast 80% of my baits.

What resin are you using? As hard as I tried

I was never able to have any luck with foam

castings. All my baits are cast from RC-3

from Alumilite. This is a Urethane Resin.

You will need a good scale to get it right.

I pour 3.5 oz of part A (by weight) into a 9 oz cup

I pour 3.5 oz of part B (by weight) into separate a 9 oz cup.

I add 3 1/2 Tablespoons of Micro balloons to

each cup.

Mix both well and keep mixed well during the process.

I then add .300 oz of each part to a 3 oz cup.

Mix well and pour slowly into mold. Pour in a very

thin stream or resin may clog pour hole before you finish.

Dust your mold with baby powder or similar and

bang molds against each other to remove excess powder.

Check TU for a live feed from Clinton on Sat, May 1st,

I may be doing this on the feed.

Good luck.

Hi Coley

Thanks for your input and nice to hear from you. I am not sure of the exact make of resin I have ordered at this moment in time as I am at work and do not have access (can't remember is more like it smile.gif ) to the site I have ordered from but what I can say is it is a polyurethane casting resin. I will email you with specifics this evening when I get home.

philB

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Hi Coley

Thanks for your input and nice to hear from you. I am not sure of the exact make of resin I have ordered at this moment in time as I am at work and do not have access (can't remember is more like it smile.gif ) to the site I have ordered from but what I can say is it is a polyurethane casting resin. I will email you with specifics this evening when I get home.

philB

I've heard you should wear respirator when using microballoons because of the way the get in your lungs. Something else to think of is plastic won't take a paint well so maybe you need to use a plasti kote primer or seal it first. Just throwing something out there.

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I've heard you should wear respirator when using microballoons because of the way the get in your lungs. Something else to think of is plastic won't take a paint well so maybe you need to use a plasti kote primer or seal it first. Just throwing something out there.

Soaking up this advise like a sponge smile.gif Thanks.

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I've heard you should wear respirator when using microballoons because of the way the get in your lungs.

I just wear a cheap face mask but I always make sure I pour these with me upwind.

Allen

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I just wear a cheap face mask but I always make sure I pour these with me upwind.

Allen

I use Smooth On Feather Lite...for my top water lures it is easy to use and it works great

don't need any micros

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Hi all

Having made wooden baits for a good while now I am going to branch out into resin cast baits. I have done a lot of investigation into resin casting and I am confident of success (hopefully rolleyes.gif). I have my cast box made and materials on order RTV silicone, polyester resin, microbubbles, plasticine and finally mold release (I know this is not really needed but wont do any harm) I also have the master bait from which the cast will be made. The finished baits will be through wired so a wire harness will be incorporated at the casting stage, so I reckon I am just about ready to go.

Some of the answers will depend on if it is a polyurthane or polyester casting resin. No baby powder with the polyester casting resin. If you are using polyurthane your job will be easier. The polyester would be do-able but you would have to do it in a couple of pours. You would have to pour 1/2 let it gel and then lay in your wire harness put the mold halves together and finish with the next pour. This stuff if fun to work with but does not handle heat well. I think polyurthane is what you want. Your last post said polyurthane so I am sure you are on the right track.

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Some of the answers will depend on if it is a polyurthane or polyester casting resin. No baby powder with the polyester casting resin. If you are using polyurthane your job will be easier. The polyester would be do-able but you would have to do it in a couple of pours. You would have to pour 1/2 let it gel and then lay in your wire harness put the mold halves together and finish with the next pour. This stuff if fun to work with but does not handle heat well. I think polyurthane is what you want. Your last post said polyurthane so I am sure you are on the right track.

Hi

Thanks for your input. Since the original post things have changed a little. I did in fact order polyester resin in error however I was not all that concerned as I needed casting experience and this has given me some. The polyester is a lot harder than polyurethane and much more brittle, so I understand, though I have found that the addition of microbaloons definitely gives a plasticity to the resin, it is also a heavier resin. I have turned this heaviness however into a positive. My first casting sank like a stone when I wanted to make a floating bait. No matter how much filler I added I could not get it to float, the best I managed was a slow sinker. The answer was simple, attach buoyancy internally which I did by attaching balsa dowel to the through wire harness, voilà, a floating bait. Problem was it then floated on it's side blink.gif. What I have done to combat this is to cast the bottom half of the bait with unfilled resin and the top half with filled resin. The bottom unfilled half acts as ballast, the top filled half acts as additional buoyancy and along with the balsa inside they now float like corks laugh.gif and the correct way up so I do not need to add lead weights. I do not wait for any to gel and pour all at once, de_molding in around 10 minutes. Full cure in around 24 hours.

I will post some pictures of the mold and cast results which hopefully will be of use to anyone embarking on the same journey. Thanks to everyone who has given their advice it has all been of use and will continue to be so.

philB

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PhilB, I messed around with the polyester resin and MB's a couple of years ago. I had the same problem as you, trying to get the mixture light enough to be able to get some lead in there to ballast the lure.

I added 3.5gm of MB's to 20gm of resin, this gave me a body density of 0.72gm/cm3 (equivalent of beech, birch, oak). This is a HUGE amount of micro balloons! It took some mixing too, as the bubbles were a problem in a mixture this thick, about the consistency of English mustard. I would spread the mixture up the sides of the mixing cup, with a knife, to release the bubbles.

Obviously, such a thick mix cannot be poured. I solved this problem by spooning into a cake icing injector and injecting into the mold. Clean-up was fairly simple, withdraw plunger and wipe excess off with tissue, re-insert the plunger and draw acetone in and out from a bowl about 20 times and set aside to dry. The acetone can be used many times, just allow to settle and pour off the sediment. Yes, bubbles still occurred. I filled these with a filler and lightly sanded.

After first use of the syringe, do not clean off the nozzle thread area, so the excess resin fills the voids and makes subsequent injections more efficient with less waste. I bought several injectors, thinking they would not last long. This was not necessary, as I did about 400 casts and the syringe is still good.

The method worked, but the density was too much for the lure I was designing. I wanted a wide action, but the density would not allow. Also, as you stated, the bodies will be brittle, but acceptable for your own use, as you know the limitations.

Dave

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Dave

With the filler added I am not so sure they are quite as brittle as I expected. They are hard but I can still scrape a tiny dent with a finger nail. The unfilled however is diamond hard and will shatter no problem smile.gif. I have got my polyurethane resin now and have just cast the first using the same methodology. Seems to have worked a treat but had to go like hell to catch both resins before gelling too much but managed it Ok. I have just cast one with polyester bottom half and polyurethane top half just as a pure experiment so don't know yet what that will be like. I am trying to get away from adding weight to keep upright and balsa for buoyancy. Still messing with em so ongoing at the moment. Thanks for your input.

philB

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I like this. Not affraid to experiment.

I did the balsa thing. It worked, but was a lot of effort.

Keep us informed.

Dave

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