Concrete Dining Table With Foam Core and Carbon Fiber Reinforcement

I do not really know why I came up with the idea of a concrete dining table but so it came.

First I looked if there was anything to buy, but what I found wasn't what I was looking for.

Either it was to thin and had a real fake surface feel or it was too heavy or not fitting into an interieur design.

Step 1: STEP1: Concept and Design

After that I summarized my requirements:

• concrete surface feel
• massive but "interieur" look
• weight <250kg

Result:

• Stainless steel table legs
• 80mm thick plate with 40mm foam core
• carbon fiber reinforcement instead of steel rebars
• 220kg

Step 2: STEP 2: Foam Core and Carbon Fiber Reinforcement

I sawed the the 40mm foam plate into the designed shape and bolted screws on it.

Then I used 50k carbon fiber roving and started to wind this kind of framework structure.

Then I used epoxy to infiltrate the rovings and let it harden.

Step 3: STEP 3: Mold & Cast

The mold is very simple: Just a few wooden beams and panels.

The foam core with the carbon fiber reinforcements was connected upside down to the top of the mold.

I removed it from the mold about 4 weeks after casting.

Just used some very fine sand paper with water to smooth it.

Step 4: STEP 4: Welding Legs

I used 80x80x2 stainless steel tubes.

I cut them with a saw (today I would use lasercutting because it's so cheap and precise) and TIG-welded them.

Step 5: STEP 5: Carry It in the Living Room and Mount It

Well 220kg and is lighter than 450kg (which would have been the weight for a "classic" concrete steel design) bit it's still heavy. So it took 5 guys to move it from the garage into my living room and mount it on the legs.

But I'm really happy with the result.

This was my first instructable and I have to admit I rather banged it out. But done is better half-done and I'm going to improve it step by step. I'm looking forward to your suggestions and questions.