Previous thread disappeared? Looking to make a Table

General Composites Discussions Composites Talk
#1

I’m not sure what happened to my post I just posted about half hour ago but I’ll type it up again…

I just have a few new questions I couldn’t find answers and was hoping for some help again. Please bare with me if you can.

I would like to make a table about 4x8 in size. I was thinking that I could get the pink insulation foam that home depot sells and do a wet overlay on one side of the foam and the two edges on the end. Then once that cures, trim it down and clean it up and then do the other side and remaining edges as well. Would the pink foam work, and would this look decent enough?

Second question is attaching legs to the table. Could I use hysol epoxy to attach some legs to it or should I rivet some folding legs to the carbon?

I think this would be a fun project to make a table. Would there be any precautions as well?

Thanks again for having a great place to post questions about composites.

Zac

#2

the table will be too weak unless your doing multiple plies of carbon fiber on each side. Way too expensive using that much carbon cloth for a table. Plus your core material would still be a huge weak spot because that is too much core thickness.

If your just going for the look of cf then overlay a wooden top.

You could laminate 2 sheets of mdf together to make it 1 inch thick or so, then bond a thin carbon fiber sheet to the top. But then if you plan on using it for a work bench there’s really no point in using cf because it will get destroyed anyhow.

#3

I was thinking more along the lines of a poker table and would like to have the lightness of carbon. I could do the racetrack in carbon only but need to find a way to make it lighter on the playing field. Maybe fiberglass the playing field over the pink foam and then the felt and that will still allow it to be lightweight…

Doable?

#4

BTW the pink foam is only .5" thick. If I did two coats would it be strong enough to handle weight of people resting their bodies or elbows on the edges?

#5

No, it will not. Thickness is always a winner when it comes to stiffness. No carbon that can do anything about it.

#6

Doing carbon layers on BOTH sides of the foam would work. You would have a good tension and compression face sheet. You just have to watch out for what resin you use, it might eat the pink foam!!! use equal plies on each face. Use enough to obviously make it strong. For that size, I would imagine at LEAST 1/8" thick. You might want to add one or 2 extra uni layers going in the 0deg direction (long ways) to keep the length pretty solid.
If you have never done this, I would personally peelply both sides. This way, if you find out that it’s not strong enough, you can reinfuse more layers on the peelply surface!

#7

Thanks riff, I’m going to be ordering supplies here in about two weeks so this should be fun!

#8

Then glue 2 or 3 sheets of foam together. Using cheap foam, then covering it with a total of 6mm of carbon makes no sense. Not even for me, and I sell the stuff…

#9

for a 4’x8’ table, that is pretty big. You can’t just laminate foam, and even if that was strong enough to be a table, it’s still just foam. I would use ONE piece of foam, not laminate it, but nonetheless, if the table is going to be a useable surface, and 8 foot long, you need something there to reinforce. Adding just a top layer it would bend, and break the foam on the bottom side.

#10

Of course you need both top and bottom laminate. However, a 4x8ft table (that is fairly large, most tables are 3ft or less in width) needs thick foam, or multiple layers of foam.

I once made a table about 8 meters long (25 ft or so) and some 1,6 meters wide (5ft 4in) which was made from girders 15cm wide (6") but became less thick on the edges, to make that sleek look that you are after as well. Basicly it was a giant surfboard.

The top and bottom laminate were designed to add to the construction as well.

#11

Good point. I guess a TABLE doesn’t care if the core is laminated. if you are making a full structure, then you risk the layers delaminating and causing the whole sandwich theory to go to pot :slight_smile:

Or just use 1" honeycomb, and 2 layers of quartz on the face sheets. I know that will hold up to a hammer or 8!!!

#12

So best theory of making a big 8’ surfboard then? LOL (while maintaining a degree of cost savings if possible)