Keep it simple... what wax do I use?

Total newby here, so have mercy.
I've made a few things with what I consider fair to good results. I'm using regular paraffin wax I bought at Hobby Lobby. When I attempted to add wax sprues that I also made of paraffin I can't get them to stick.. using a soldering iron like I see in videos, it just instantly puddles and makes a weak bond if at all.
Little help?

 

When I bought the paraffin, they had bees wax , paraffin, flax wax, soy wax, and god knows what else. I finally just guessed.
Why is beeswax better?

 

I have a couple things going. First off, I worked fighter aircraft my whole life so I'm working a model of an F/A-18 Hornet. I built the kit and am now shaving all detail and filling gaps and voids to create a smooth "stylized" desktop model. I'll create a wax positive from silicon and then cast in aluminum.
If you have advice on what silicon to use, what wax, and what investment, I'm all ears.

 

The model is about 8-10 inches long and almost as wide.
You think I should use ceramic shell or investment block? I'm trying to figure the best path without continuing to buy the wrong stuff all the time...
I'll dig around for a wax source.

 

Thank you. There's is definitely a lot to learn here. Between not knowing enough to ask intelligent questions and trying to read forums where folks are talking way over my head, it's a slow process.

 

Here is a link for the brown microcrystalline wax I use.
If you decide to run shell, do some digging on my threads in the lost wax section. I run Ransom & Randolphs suspendaslurry. It's dead nuts easy, no mixing. Costs a little more, but worth it.
http://arizonasculpture.com/j-mac-microcystalline-wax-2-ab150/ 1 slab will be PLENTY of wax for you for many projects. You will recover it during dewax, clean it up and use it again.

 

Thank you sir. I just returned from a week+ vacation. I’ll probably continue to piddle around with paraffin while I learn and get the good stuff on order. Dewaxing is an issue because I’m using the DIY foundry and it just falls to the bottom and burns up. Would a standard kitchen oven work for dewax? I can grab those off Craigslist all day long.... come to think of it, my buddy next door has one in his garage....

 

A kitchen oven will not work for ceramic shell dewax. It's too slow and the shell cracks. A kitchen oven would dewax solid block investment as that is done slow. BUT it will not get hot enough to prepare the investment to accept metal. So your options is a harbor freight weed burner to dewax or boiling water method like I use. Take a peek at my youtube channel. I demonstrate both methods. Ceramic shell is the cats ass, but comes with extra support gear. If you are going to run shell, I highly suggest you find an old pottery kiln. I paid 25bucks for my cat piss kiln. Ya just gotta look. After the was is removed (called dewax) you then have to heat shell super hot before pouring metal. This burns off anything organic, drives off moisture and preheats it to accept the really hot metal so it wont shatter.

 

Thanks Jason. How do I find a YouTube channel??? I'm a little dense on YouTubeing...

 

Look at my signature. click that

 

I'm feeling dumberer than before..
Sigature?

 

This bit:
-----
Socialism in a nutshell...
You have two cows. The "State" takes one away and gives it to your neighbor, who doesn't have a field to keep it in.
https://www.youtube.com/user/jagboy69

 

Found it. Thanks

 

Next perplexing question if the day..
When she’ll casting, why build a big sprue / sprue cup to feed the molten metal in through the bottom Vs simply pouring it in from the top?

 

The added weight from above creates pressure to feed the metal through the hollow shell. The cup makes for an easy target. Nothing is wasted, after you cut your part out, the sprue, feeders and cup get melted again next go around. Funny thing, the wax costs more than the bronze.