Helmet problems

[PMS Solstice GI]

When I did my clay mold, it wasn't lopsided. But when I molded my plastic it came out lopsided. What did I do wrong?

 

[NZTK]

What type of mould did you make? what type of plastic did you cast? did the mould have a rigid jacket? did you mix the plastic and catalyst correctly?

 

[PMS Solstice GI]

What type of mould did you make? what type of plastic did you cast? did the mould have a rigid jacket? did you mix the plastic and catalyst correctly?

I used exactly what Adam used. Rebound-25, Thi-vexII, Plasti-paste, and Smooth-cast300. Yes I did have a mother mold or outer jacket. Here's a picture.

 

[mgrmax]

That one has me stumped. Was your Rebound mold snug against the outer jacket? Did you have the outer jacket bound w/ bungies or rubber bands?

 

[Xavier]

what did your helmet look like to start with (the mother)

 

[AoBfrost]

The plastic should take the exact form, it looks like the mother mold may be messed up or the plastic wasnt set against the walls of the mother mold.

 

[rowan]

perhaps you took it out of the mold to early? did you give it time to completely cure/harden? (you have to wait until the smooth cast 300 is cold to touch)

 

[PMS Solstice GI]

perhaps you took it out of the mold to early? did you give it time to completely cure/harden? (you have to wait until the smooth cast 300 is cold to touch)

Yea, I left it in there over night.

 

[Robogenisis]

Wow. That pull looks as bad as some of the pep helmets I've seen.

Now, I have no molding experience, but:

1. Could you please post some pictures of the mold, and everything related to the mold,
2. Did you make sure that the Rebound mold was snug against the inside of the jacket?
3. When you removed it, was is that way, or did is smush after you pulled it out?
4. Did you make sure to keep rotating the mold until it was hard enough to keep it's shape?
5. Did you use the right plastic to catalyst ratio?

My guess is that you didn't rotate the model enough, and set it down right-side-up, and the top smushed down inside the mold because it was still soft enough to smush.

 

[PMS Solstice GI]

Wow. That pull looks as bad as some of the pep helmets I've seen.

Now, I have no molding experience, but:

1. Could you please post some pictures of the mold, and everything related to the mold,
2. Did you make sure that the Rebound mold was snug against the inside of the jacket?
3. When you removed it, was is that way, or did is smush after you pulled it out?
4. Did you make sure to keep rotating the mold until it was hard enough to keep it's shape?
5. Did you use the right plastic to catalyst ratio?

My guess is that you didn't rotate the model enough, and set it down right-side-up, and the top smushed down inside the mold because it was still soft enough to smush.

I think that might of been it, but i'll put some pictures up.

 

[NZTK]

Did you have the flexible part keyed so it wouldn't come away from the jacket while you were slushing? Its the only thing I can really think of without seeing all the parts used.

 

[PMS Solstice GI]

Did you have the flexible part keyed so it wouldn't come away from the jacket while you were slushing? Its the only thing I can really think of without seeing all the parts used.

I only put the plasti paste on the back part because I couldn't get it off the front and it broke in 100,000,000,001 pieces.

 

[rowan]

Ok, not 100% sure what that meant, which part do you count as the back? pics would help us greatly!

 

[Sean Bradley]

The weight of mold matrial on clay can be quite significant. If you aren't very gentle with it, you can distort your sculpt during the moldmaking process.

But I think we'll wait til we see your pics to draw a verdict..

 

[PMS Solstice GI]

This is the back half with the shell mold.

 

[Sigma LS]

Looks like the front of the mold is squished anyway. You need a shell mold on the front to hold it in place.

 

[docbytes]

It looks like the problem I had with my first mold, I did not put a lip on the 3-outer pieces to my mother mold. since I didn't lip them to clamp them together the mold would distort the more it was moved, this causes the shape of the helmet come out very misshapen.

 

[PMS Solstice GI]

When you have the slit or the cut down the back of the helmet mold, how do you keep the plastic INSIDE the mold instead of leaking out?

 

[NZTK]

generally your jacket keys should keep the whole thing together. A common method of keying your jacket is to use copper roofing shim to make a zig zigged seam that you glass up against, so when you do both sides and take the copper out, it slots together without moving, then you drill holes in the seam and bolt it up. You leave the neck open so you can pour your liquid in, then you slush it. I mean no offense by this statement but, the picture of the mould you made looks pretty bad. You will probably need to remake it.

 

[PMS Solstice GI]

generally your jacket keys should keep the whole thing together. A common method of keying your jacket is to use copper roofing shim to make a zig zigged seam that you glass up against, so when you do both sides and take the copper out, it slots together without moving, then you drill holes in the seam and bolt it up. You leave the neck open so you can pour your liquid in, then you slush it. I mean no offense by this statement but, the picture of the mould you made looks pretty bad. You will probably need to remake it.

Yea. I don't have the bottom part of the mold thick enogh to cast. But the seam in the back wont stay closed when I put the mother mold on. (tell me if I could or couln't do this)I tried to put Duct tape over the seam.