Epoxy Resin Concentrator Manufacturing and Lamination

[nialaz]

wazaibzh,

I'm still not sure what the gel coat is for.
Until then I thought that the gel coat became a constituent of my mold. But if I understand correctly (this time!?) It will become a constituent of the piece that I will mold.

More precisely it is the gel coat that will constitute the 'useful' surface of my room and on which I will stick my mylar.

That's it ?

[wazaibzh]

you can perfect the surface of your mold with a gel coat but it will be necessary to use a gel coat for mold or finish which is different from the one used for a piece or it will be necessary to add an adjuvants ...
we put a gel coat on the mold (before the resin and the fabric) in order to obtain a clean finished parts with a beautiful appearance of the desired color ... this avoids a finishing of the parts and the gel coat protects the resin of the UV ... can resist chemicals, abrasion or food ...
the gel coat is a soft resin, tinted ... which in addition facilitates demolding.
so you understand!
Do you have a lot of coins fired in your mold?

[nialaz]

Thank you for the answer, it seems clear to me now.

I think to make six pieces which makes me a reflective surface of 0.7 m2 about.

There's more than trying the molding! 3 days the plaster mold is done and I still have to wait because it is still dry.

[nialaz]

Hello,

I just made my stratification. Not easy !


After finishing my plaster mold to properly adjust the surface and plug the pores I spent two coats of paint with polyurethane resin.
3 Layers of liquid release wax and tonight layering.

Yachtcare polyester resin. I took the part not to put gelcoat to see already how it goes with the resin.
After applying a first layer of resin I put the mat by tearing it. Then I added the resin until absorbed. After a good ten minutes I saw bubbles up to 2 3 cm in diameter in the middle of my mold. On the edges it was fine. I had made a debulleur with a threaded rod and washers and despite that I could not evacuate these bubbles. In the end I went with a nail to drill and brush to evacuate the air.
But there are still some left.
Nevertheless, I put on a second coat and stopped there.

I conclude that the option of putting the mylar in the bottom of the mold is not viable given my mastery.
I'm afraid after demolding a very ugly surface ...
Assuming that I can not do better with the resin, will the gel coat allow me to tolerate this poor result by ensuring a piece with a good surface finish and respect for the shape? Once he is tacky is he strong enough to resist my abuse of resin?

Finally, I tore the mat. Finally, would I not have done better to cut a mat corresponding to the surface to be adjusted and to deposit it thus?

Tomorrow I demould we will see the damage!

[Other]

Hello

After finishing my plaster mold to properly adjust the surface and plug the pores I spent two coats of paint with polyurethane resin.
3 Layers of liquid release wax and tonight layering.

On a plaster pattern well painted with laitex then I wax generously with beeswax, for debulking there is a debuller rollers, there is also a propitious moment during the (draw) of the resin for the debuller well count the drops of catalyst ..
You can do the work cold you have more time once the piece ready you go back to warm ..
Once unmolded, correct the defects and the polyester mold is ready to strengthen the structure of wood embedded in the outer fibers of the mold.
The direct gelcoat on the mold gives a superior finish to the resin mat, although its structure is less resistant

Andre

[nialaz]

Good...
I can do it again because I broke the mold by unmolding.


Feedback:
there was reaction between the resin and my mold. Probably the painting that I put and despite my 3 layers of wax.
Did I apply the wax well ?!
Then I actually metered the hardener because even after 24h00 the first layer of resin was still pasty or so it is the reaction that blocked the polymerization.

So it's not very conclusive!

[wazaibzh]

Hello nialaz!
pity you're broken your mold!
the reaction that you had little come from the paint in direct contact with the resin ... but can also be wax ...
for the first layer you had to go wrong in the percentages. for polyester between 1% and 2% (catalyst) should leave you time to do the lamination.
adapt your layers of mat to the size of the piece and cut or tear the corners to fold the fabric around the edges.
before laminating on a gelcoat it must be hard but just a little sticky (no trace on the finger).
before redoing a new part, do a test with your product by laminating on melamine or other.
What is your liquid wax?

[nialaz]

Hello,

I used Soloplast Liquid Wax.
I will have to redo my mold. I intend to change strategy and instead of going through a polystyrene model I will directly make the parabolic plaster form. During the stratification I will form around this shape to make my edges.
That way I'll be able to separate the demoulding from the edges and the one from the parabolic surface. And therefore reduce the efforts.
The other advantage of making the plaster mold directly is to be able to make it stronger than before.

The problem that remains to me is that of the adhesion of polyester to plaster knowing that I put 3 layers of wax. I am therefore wary about the effectiveness of the product or my method (brushing and drying 1h00, buffing and brushes back ... 3 times)

On the internet I have seen other people who have encountered this problem of adhesion despite the resin and the gel coat.
I also saw on the forum carving (http://sculpture.forumactif.com/forum.htm) that paste wax or polyvinyl alcohol could be used.
What do you think ?

[wazaibzh]

soloplast wax is the w2?
I prefer personal wax paste!
Since you have to pull several pieces well reinforces your tone and for the edge they should not be at right angles but slightly inclined to help demolding.
if you make demountable mold edge either on the resin does not block the infiltration disassembly ...
to saturate the plaster uses acrylic. because the plaster and its porosity
before putting the gel coat the mold must be nikel, shiny, smooth ... a drop of water must be able to roll on without being absorbed by your mold.
put pictures of your mold!
the concentrator is to heat water?

[nialaz]

Thank you for these tips.

It is indeed to heat water and also for curiosity.



To saturate the plaster you recommend acrylic ... you talk about painting I think.