Advice on using Soric in corners.

General Composites Discussions Composites Talk
#1

I’ve been in the habit of clipping my Soric as I make it fit into the corners for the CF prototypes I’ve made. They usually seem nicely butted together when I do this, however the attached picture shows a study casting I did, exploring alternative materials/looks, methods, etc. (Obviously glass this time.)

I cut the Soric the way I usually do, but as you can see it’s widely gapped on the, (two adjacent), corners. :frowning:

Because I’m trying not to use spray adhesive any more, I suspect the material is shifting. Although this looks pretty bad, I’m more concerned about what this does to the strength of the product in those corners.

Obviously, I need to pre-cut these on a table, and not depend on my apparent, hand in mold, scissor skills of a five year old. :smiley:

[ul]
[li]What do others do?
[/li][li]Can you glue Soric?
[/li][li]How can I get these corners tight and solid?
[/li][/ul]

#2

Sometimes you need to cut little pie shaped pieces to fit into the gaps.

Is the carbon tow squiggles an artistic variation? :smiley:

#3

Do you like it? :slight_smile: I have collected a box of that tow. I thought it would be fun to throw some in the mold after the clear coat, showing the Soric honeycomb, along with some prototype logos and various spray paints. I also tried an old embroidered cub scout patch too. (The iron-on glue makes it tough to wet out though.) I also tried some velcro on the inside, (just the claw side of the velcro!), and I put a QR barcode on the inside for testing possible part tracking options. Out of the 9 tests in this infusion, 4 worked great, 5 were learning experiences.

This was my first dual mold infusion. Wow! - No time for snoozing!

I had switched to a puck type connector instead of a Tee, a couple back. I was use to a certain level of roughness with things. When I clamped off the inlet, I didn’t realize I popped the hose off the recess of the puck! The weight of the hemostat bent the sticky tack and caused a breach. :frowning: Live and learn! :wink:

Pizza wedges? That makes sense… Esp. for CF. There’s talk about having a glass version of the product, (hence my testing), honeycomb included. Gotta have perfect corners if that’s the case.

Some glue testing:

[ul]
[li]Super Glue - Gets absorbed into the Soric!!!
[/li][li]Contact Cement - Seems to work physically, albeit a little too viscus.
[/li][li]Elmer’s Glue - Don’t know yet. :wink:
[/li][/ul]

#4

Hey jap,

I am going to be making corners just list yours in a box I’m trying to make. Is it impossible to get carbon fiber to form around the corner? I was hoping I didn’t have to cut the fabric :frowning:

#5

For this mold, the depth of my box is relatively shallow. (i.e. ~2"), and my corners are 1.25" radius. For me, I can easily stretch at the corners of the reinforcements to make them sink without problems. I’m sure there are weave/weight considerations to consider. I’ve used ~600gsm Plain and 2x2 Twills. I suspect the more square the mold, the more depth is possible, at the sake of wasting material.

Be aware: When you stretch the corners it bunches the fabric there, making it more dense, whilst taking away from the flats. Thicker reinforcements take longer to wet out!!! If I have a problem, it’ll be in those corners.

BTW, I have a complementary part to this which is 6" deep, which I just cannot stretch and I have to cut. Still working on getting the cut line just right. :smiley:

#6

My box is going to be 13" deep with the corners about the same radius. I will be layering multiple layers of kevlar and CF to add strength since I’ll be using this as luggage :slight_smile: I’m thinking I may need to cut the first layer though. Thanks for saving me some trouble I think haha.

#7

You going to have to have seams somewhere. Doing it in one piece is a physical impossibility.

#8

Interesting questions… I thought that laying without adhesive would cause it to shift. You have proof there.

But why not use spray adhesive? because of the structural issues? delamination?

You should try Zyvax StayZ Epoxy Spray interface, although it is a little more expensive, it merges with any epoxy resin system and takes on its properties. Thus the structural integrity of your part is not compromised.

I have used it with very good results and no residue whatsoever! In your case I would definitely give it a shot.

good luck

#9

Thanks for saving me the trouble of figuring that out. My plan is to take a piece and wrap it horizontally around the walls and then put another piece along the bottom so there would only be one seam that you can see with the box sitting up. Is it better to have the seam on a corner or on a flat part? If the seam is on a corner, will that effect the strength of the box?

#10

You can put the seam in the corner, then the subsquent layer seams can go whereever you choose, because you cant see them anyway, thus it will be strong.

#11

Whats soric like when trimming? Like if you over lap the part omto the flanges and trim back is there any noticeable diffrence on the edges

#12

Do you mean, when trimmed, what do you see of the core? Soric just shows up as a white layer. The CF is quite thin by comparison. It takes a 90 degree just fine, if that’s what you’re wondering.

Soric has been wonderful! A had originally used hand cut end-grain balsa wood as my core material. Tough, but what an unwieldy mess! Soric makes it easy and makes for a very rigid part. I’ve repeatedly run my Mercedes over my part and hit it big time with a sledge!

#13

I mean the core is not noticeable on a trimed edge? I will have a play :slight_smile:

#14

Here’s what my stack looks like cut. Note the slightly thicker carbon fabric in the corners where it’s been bunched by stretching.

#15

Did you use 2mm or 3mm soric for this? I’m really liking what I read about this core! This could cut the cost of my layup considerably since you don’t need infusion mesh or peel ply. What kind of resin did you use and also what vacuum bagging?

#16

This is Soric SF3, (i.e. 3mm)

Don’t go throwing out your mesh & peel ply just yet! I had the same idea, until I infused on a cooler day. (Cooler meaning 68 deg) The infusion became disturbingly slow. I now use mesh and peel ply in the middle, about half way, and throttle my initial flow. (I infuse in the center.) Plus, I believe Soric has a directional flow to it. Peel ply also gives a nice matt interior finish,

I use Adtech EL-360 or 820, and use Strechlon 800 bagging film.