|
|
Post by mercbill on Nov 26, 2021 17:07:27 GMT -5
I'm making a complex part using Slow Set. I will be combining several parts to make a larger master part so I need a glue to hold them together so I can make the final mold.
Also, I used clay to build up some areas on the first parts I've made. There are rough areas that can't be sanded out so I need a fairing putty I can apply that will stick to the slow set and but be soft enough to be easily sanded.
Lastly, the Slow set is pretty flexible after it comes out of the mold. Says rigid but it's not rigid. I'm mixing small batches, about 20 ml or less so far. I'm doing my best to pour it to the level line on the little cup. Seems I need more hardener than resin. For this small amount, how much extra should be put in to make the hard come out so it's not flexible?
Thanks, Bill
|
|
|
|
Post by notoes on Nov 29, 2021 9:58:01 GMT -5
I use Locktite Professional super glue, sticks harder than I want sometimes but you can also use a little drip of the Slow Set as the glue too.
If it's just on a master part that you will be making a mold of, why not use Sculpey? It can be baked right on the Slow Set and is easily sanded - I do this myself on some of my castings when I need to add details to a resin casting. Just another option if the parts are small.
The flexibility is probably due to the thinness of the part being cast as I see this in my own castings where I have thin walls. It really won't be much difference how much hardener you add if the walls are extremely thin - can you show a picture of the problem areas or say how thin the walls are? Also is it still flexible after it has hit full cure? Sometimes hitting full cure will harden up the part a little more with the slower curing resins.
|
|
|
|
Post by mercbill on Dec 6, 2021 17:21:11 GMT -5
I wasn't aware I could put sculpey in an oven to harden it up. That won't melt the plastic part I've made? I ended up using JB weld as a fairing compound. It worked out well.
I'll get some Locktite professional glue and give that a try.
The parts in the photo are automotive flag emblems. I want the flag poles to cross at the bottom, which is why I need to extend them about a quarter inch. That'll be a lot of work but it'll look better. as you can see the flag poles are very thin. I ended up adjusting the volume ratio of the two parts and the finished product is much stiffer. It seems too much part A makes the part soft and flexible.
One more question, can the Slow Set or Performance 80D be chrome plated? It seems there are a few methods. Vacuum Metalizing is the best option but there are spray options too. (I'm getting a Performance 80D kit delivered on Wednesday) I hope this is better than the slow set.
Attachments:
|
|
|
|
Post by notoes on Dec 7, 2021 8:34:16 GMT -5
Sculpey is meant to be baked in the oven, the directions are on the back of the package. But if any part of the part is plastic - DON'T put it in the oven as you will melt plastic. Since you added JB Weld into the mix, I'm not sure if it would be safe to put that into the oven - be sure to check out what it says on the package and if that doesn't answer that question then go to their website and see what that says.
You should be able to find it easily, I usually get mine at Lowes.
Then if that works for you, I'd go with that. They look good otherwise.
Slow Set should be able to be colored just like RC-3, be sure to put a primer coat on it first - there's a couple ways to do this but I like to spray in a clear primer into the mold cavity so it bonds better with the casting. Now as to Performance 80D, I'm not sure how to color that so you'll need to refer to the technical data sheet on it.
|
|
|
|
Post by mercbill on Dec 7, 2021 12:19:13 GMT -5
Thanks for all the good information. For chrome plating, I was going to send it out to a shop or try one of the spray chrome products. I'd really like to color the resin instead but I don't think a chrome color exists. All of the chrome paints I've looked at are simply a shade of silver, which won't be satisfactory. The car world is picky. They want real chrome, weak substitutes won't be accepted.
|
|
|
|
Post by notoes on Dec 13, 2021 9:46:31 GMT -5
I can understand that. You can always spray the mold itself with a primer before casting in it that way the primer will bond with the resin while the resin is curing (best way to get a good bond) and then when you send it out to a shop, the chrome would have something to bond to - it's the same way as a primed resin piece will hold paint better than an unprimed resin piece, resin sticks to resin but paint needs something "extra" to bond to as it doesn't bond well to cured resin. Plus with it primed already, the shop will thank you for giving them a good surface to add chrome to.
|
|
|
|
Post by mercbill on Jan 5, 2022 16:42:29 GMT -5
I can understand that. You can always spray the mold itself with a primer before casting in it that way the primer will bond with the resin while the resin is curing (best way to get a good bond) and then when you send it out to a shop, the chrome would have something to bond to - it's the same way as a primed resin piece will hold paint better than an unprimed resin piece, resin sticks to resin but paint needs something "extra" to bond to as it doesn't bond well to cured resin. Plus with it primed already, the shop will thank you for giving them a good surface to add chrome to. Thanks for the tips and suggestions.
So, for painting a mold
Rather than primer, can I use a finish paint like testers so I can paint different colors in different areas? Do I need to let the paint dry before pouring new resin?
Thanks again
|
|
|
|
Post by notoes on Jan 13, 2022 10:00:07 GMT -5
I'm not sure about that as I've always recommended a clear primer but I'm thinking it should work - can't promise anything as I haven't tried it myself. Yes let the paint dry before adding resin as the resin will bond better with dried paint and the paint will stay in place if it's dried first.
|
|
|
|
Post by mercbill on Jan 13, 2022 14:39:12 GMT -5
I'm not sure about that as I've always recommended a clear primer but I'm thinking it should work - can't promise anything as I haven't tried it myself. Yes let the paint dry before adding resin as the resin will bond better with dried paint and the paint will stay in place if it's dried first. Update. I had some metallic tempura paint on hand so I gave it a try. I brushed it on with a small brush. It didn't stick to the mold very well and didn't cover very well either so I let the partial coat dry and then added 2 more coats (until there was full coverage). The part after casting didn't turn out well at all. the paint didn't bond with the resin very well. It could be scrapped off very easily. I'll give spray primer a try now. |
|
|
|
Post by notoes on Jan 26, 2022 6:21:30 GMT -5
I've painted with acrylic paint a long time after a casting has cooled just to see what it does and half of it scraped off like that too. Please let us know how the primer works for you. Once that's on and bonded, you should be able to use any paint you want over top of it.
|
|
