FAT wood

[gabepari]

I got tired of laminating 1" MDF for molds


5190


5191

So, I found some 2" MDF. Still need to glue it up in layers, but it should save some time. And less glue lines in the mold.


5192


5193

We'll see how it works.

Gabe

[Brady Watson]

Pretty cool, Gabe. Not sure if Trupan would work for you or not, but I've been able to get Trupan Ultralight in 50mm thickness for about $115 a 4X8. I think it is 60% the weight of MDF.

-B

[gabepari]

I paid $99 a sheet for 49x97. I would like to use Trupan, and I have a local source, but my customer has issues with the ultralight. It compresses more than regular MDF and it effects the thermoforming process.

Trupan sure sands better at the glue lines though.

On another topic, I priced some RenBoard for a tooling job. 20"x60"x6" piece was close to $1800. Youch!

I need to order up some of that machinable plaster and see if it will work for thermoform molds. That way I can eliminate the glue lines all together, except for molds taller than 7".

Gabe

[Brady Watson]

Gabe,
I've used Rayite100 by USG. The only supplier that wants to deal in less than pallet loads is Chembar in OH. It needs to dry for a solid week, maybe more, otherwise - it is not fully cured. While the Bot will have no trouble carving it, picture an eggbeater full of batter all over the machine. The mold needs to be roughed out, let stand to dry, then 3D carved to tolerance.

To be honest, carving the MDF is butter compared with dealing with some of the alternatives, both in headaches & expense.

-B

[garyb]

Gabe, had just run 2 thermo tools from 48x48x2 renboard, direct out of pacific was 1/2 the cubic ft price you paid, got you for the 6" stock. It may be good heat resistant but to get good detail blows, about the same detail as cutting #15 PB.
We switched to MDF on the last ones and they went a lot better

[myxpykalix]

Man oh man...I can barely move a 3/4" piece of mdf, i can't imagine how heavy that 2" thick stuff is. Makes me tired just looking at it.

[gabepari]

MDF has been working great, but when layering very large molds with feathered edges at the glue line, I'm struggling with a glue that can handle the heat cycling without separating. I'm going to try some urethane glue, just need to figure out a good way to spread it over large surface areas. Is there a spray-able urethane glue?

Gabe

[gabepari]

Jack, the mold on the trailer weighed close to 800 pounds
That was the biggest of four.

Gabe

[Brady Watson]

Gabe,
Have you tried epoxy with a little bit of microfibers in it? You wet out each layer and wait for it to soak in. Then mix up a new batch with microfibers to make a very thin paste and then laminate. Vacuum bag if you want it to be ultra tight on the gluelines.

-B

[chiloquinruss]

Jack -"Man oh man...I can barely move a 3/4" piece of mdf," I was thinking the same thing!
I have a roll around cart to move my stuff but my stuff is nothing compared to that! Ouch!
Russ

[wberminio]

Russ/Jack
I'm with you both!
I gave up on MDF and melamine years ago.
I couldn't deal with the weight and the dust.
I realized the benefits of Trupan way before I got my Bot.

Erminio

[jhicks]

Gabe WOW, thats cool but maybe a hoist is in order. Maybe you should move your bot to the supplier and cut there.LOL

[gabepari]

I have a few hoists in the shop, but sadly none of them are near the bot


I've been kicking around the idea of doing a vacuum crane, and gathering parts, but I think I'm going to re-task my little Gast pump and try vacuum bagging. Sometimes the shape of the mold doesn't make it easy to use screws as clamps, and when your laying up full sheets of MDF it's hard to get enough clamping pressure with just weights.

Brady, I'd like some more info on the epoxy with microfibers.

Thanks,

Gabe

[Brady Watson]

Gabe,
Shoot me an email to discuss offlist.

Thanks!
-B