Double Clear Pour ????

[jaywood1207]

I am working on a project that I want to do a double pour on. Will there be a "weld" line for lack of a better word where the first pour and the second pour meet? Pour number 1 would be fully cured and turned before pour 2. Would the area I turned need to be sanded and polished or would a turned surface with a skew give me a nice unnoticed joint?

I am leaning towards alumilite but may use PR if that matters and both pours would be clear. Any information from those that have done this before would be greatly appreciated.

Thanks

 

[micharms]

Jamie:
I have done a couple of clear double pours using alumilite and did find that there was a noticeable weld line between the layers.

Michael

 

[jaywood1207]

Jamie:
I have done a couple of clear double pours using alumilite and did find that there was a noticeable weld line between the layers.

Michael

Hmmmm. Not exatly what I wanted to hear. Thanks Michael. Back to the drawing board.

 

[its_virgil]

No "weld" line, as you call it, using polyester resin.
Do a good turn daily!
Don

I am working on a project that I want to do a double pour on. Will there be a "weld" line for lack of a better word where the first pour and the second pour meet?

 

[jaywood1207]

Thanks Don. Any suggestions on which PR to use? Looking for something durable but not brittle and since I have very limited experience with casting something that doesn't have a huge learning curve.

 

[its_virgil]

I think most of us the cast polyester resin use Silmar 41. There are several places to purchase it. Many of us get it from US Composites: Fiberglass , Epoxy , Composites, Carbon Fiber - U.S. Composites, Inc. . They have a link to Silmar 41 on their homepage.

I have only double cast without any turning. Pour...cure...pour. But, I suspect that turning and polishing would be OK prior to the second casting. Just clean the blank good prior to doing the second cast. Maybe someone who has done what you are wanting to do will add more input.

Do a good turn daily!
Don

 

[jaywood1207]

Thanks for your help Don.

 

[BSea]

I know that SDB777 tried to cast broken pieces of silmar in more silmar to get a kind of mosaic blank. But the pieces which were fully cured wouldn't bond well with the new silmar, and the blank would break apart when turned. He had to use CA to keep it together as it was turned.

That really doesn't apply to your weld line question, but it might be something to consider depending on how deep the 2nd layer will be after turning.

 

[thewishman]

Not pens, using epoxy resin:

You, Me & Charlie – YouMeandCharlie.com is a creative digital playground for users to inspire each other as friends and artists. | You, Me & Charlie

 

[Marko50]

Jamie, I've done a couple of double pours with Alumilite and found a couple of things out. I never get a "weld" mark if I do the second pour within a day of cure and leave the casting in the mold. If I wait longer than that I do get weld marks. I don't know the chemical reaction that is taking place but it must have something to do with exposure to oxygen, maybe? (not a chemist. I just fly planes) All of my double pours have been clear pours. Are you using color?

 

[jaywood1207]

Jamie, I've done a couple of double pours with Alumilite and found a couple of things out. I never get a "weld" mark if I do the second pour within a day of cure and leave the casting in the mold. If I wait longer than that I do get weld marks. I don't know the chemical reaction that is taking place but it must have something to do with exposure to oxygen, maybe? (not a chemist. I just fly planes) All of my double pours have been clear pours. Are you using color?

Thanks. I would have to do in 2 separate molds and it would only be clear for now. Maybe tinted down the road.

 

[JohnU]

I know that SDB777 tried to cast broken pieces of silmar in more silmar to get a kind of mosaic blank. But the pieces which were fully cured wouldn't bond well with the new silmar, and the blank would break apart when turned. He had to use CA to keep it together as it was turned.

That really doesn't apply to your weld line question, but it might be something to consider depending on how deep the 2nd layer will be after turning.

I've done this several times but not had any problems. I don't know his process but with mine I just poured left over resin in a cup and then cut it up on the bandsaw and later mixed it with light tinted pr using mica pearls and 3 drops per ounce of hardner. I'm wondering if the amount of hardner used in one pour compared to the second or the type and mount of color pigments used create these issues.

 

[BSea]

I know that SDB777 tried to cast broken pieces of silmar in more silmar to get a kind of mosaic blank. But the pieces which were fully cured wouldn't bond well with the new silmar, and the blank would break apart when turned. He had to use CA to keep it together as it was turned.

That really doesn't apply to your weld line question, but it might be something to consider depending on how deep the 2nd layer will be after turning.

I've done this several times but not had any problems. I don't know his process but with mine I just poured left over resin in a cup and then cut it up on the bandsaw and later mixed it with light tinted pr using mica pearls and 3 drops per ounce of hardner. I'm wondering if the amount of hardner used in one pour compared to the second or the type and mount of color pigments used create these issues.

Scott could probably tell you more, but he took solid colored blanks, and broke them into pieces, then cast the pieces with a different color. I'm guessing he used 3 or 4 drops per ounce since I was the one who showed him how to pour. I don't think he's tried it since that 1st experiment.