Problem Child scale hydro

[drwayne]

Looking the business.

[Fella1340]

Cool project guys, looking forward to seeing this come together

[larryrose11]

mickieb49,
drwayne,
Im following closely!
I also plan on making my own hull from CAD -> Plug -> Mold -> Resin infusion.
On the plug: I assume that the wood is MDF or HDF?
What is the plan on finish the plug, and can you document it?
On Molding: Whats your plan? I have read a lot about using a epoxy / FG / CF and vacuum bag to make the molds. Epoxy does not shrink like polyester, so the molds don't warp. You know all about vacuum bagging.

[mickieb49]

Hi Larry,
The plug on this one is MDF, larger hulls i will use Polyurethane high density foam due to the weights associated .
I will be documenting the whole build of the molds here . But wont be able to document more machining untill late next week as my machine has decided that the controller needed to quit , so $400 later , new controller, i am hoping i can continue machining then.
For the Molds, i will be using Poly resins, too much cost associated with epoxy, and honestly adding a few more layers of reinforcements aleviates the benefits of epoxy in the molds .
For the hulls, my resing pump is only a Polyester resing pump, as it mixes the catylist in at the head. 5cfm vacuum pump. Was going to go with silicone rubber bags for the infusion, but the setup of nearly $1500 for the silicone may well not be worth the expense, so for the imediate time i will be using the conventional plastic bagging material.
We have a little way to go before the resins will be applied so stay tuned mate, there will be more to come.
Mick

[Shooter]

well started machining out the lower tub, not too long now.[ATTACH=CONFIG]127257[/ATTACH]

Nice. Is that MDF? I'm doing a cowl on a shopbot, but I can't find MDF thick enough. I suppose I could glue a few sheets together? Any recommendations? Thanks.

[mickieb49]

Shooter,
I laminate how ever many pieces of MDF together to get the required thickness, just use a good quality glue.
Mick

[larryrose11]

mickieb49,
On molds: I thaught that Poly resins had a 5% or more shrinkage, which can lead to warping of the mold. Correct?
Epoxy has less than a 1% shrinkage.

I could imagine a process where once the black tooling gel-coat is applied and cured, a vacuum bag process is used to make a mold. Lots of FG and hex foam core are layered up wet, and a few more layers dry are put on top to soak up the extra resin, and function like a breather. the entire thing is put inside of a large vacuum bag.
Wouldn't this produce a mold with LOTS of fiber, minimum resin, and max strength?

[Shooter]

Shooter,
I laminate how ever many pieces of MDF together to get the required thickness, just use a good quality glue.
Mick

Thanks. Do you use epoxy? or does wood glue suffice?

[mickieb49]

larry,
one thing you have to remember with the shrinkage you are so worried about is that this is on a plug, providing you leave the mold to cure on the plug for about a week, there is literally 0% shrinkage. afterall it has nowhere to shrink as the plug is holding it in shape When you lay up a hull, again providing you dont pull out the hull prematurely then it will have minimal shrinkage.
Yes you may be right about using a vacuum bag to create the mold, but also you will be creating more unecessary work for yourself, remember that this is a mold and weight is not a issue, if you take a little care laying up the first reinforcement layer, you dont need the bag .
shooter, i just use exterior wood glue, its the strongest..

[drwayne]

What . ... you're not finished yet ?
Lol

[RandyatBBY]

Looks good! yours is 44 inches? I did mine at 37.5 so the Chrysler hemi looked like a Keith Black.

[mickieb49]

Yes Randy, mine is going to be 44", will be doing 2 sets of sponsons for it, one for oval racing and another set for SAW. Also going to machine out a 32" version too for the electrics, but that may be little way down the track.
Yours is looking great too mate, looking forward to these both finished.

[drwayne]

I've a pair of special order SSS5684 and a pair of TP 5670 ready to bolt into this 44" rocket.
We'll see what runs the best ! And sell the others Lol

[mickieb49]

just in the middle of machining the plugs.

[drwayne]

Woohoo.
This is looking far more advanced than what we spoke of a few days back !
Impressive work Mick