Well, as expected, our MDF moulds are one shot only. I am really happy with the foil skin that emerged, but the mould didn’t survive and is off to mould heaven.
All four skins are completed now, so it is time to move onto phase 2, putting all the bits together.
It looks like it is time for design number 2, and another $3 worth of MDF in the machine for my “spare” main foil. That’s why they call it a development class 
Very impressed. Do you want to borrow a pump?
Who gives a cracker about the mould – $5 worth of MDF. The foil looks cool:-)
Wow – that 12k carbon looks very nice. Why did the mould fail? Is it lined before moulding or do you put peel ply in there or none of the above. Nice work regardless.
Gilly … I already did
I bolted to Dave’s and grabbed it. I am returning it tomorrow. I just bought a new one on ebay for $159 and will pick it up on Monday.
munter – The mould went through the usual release process, which consists of several coats of mould release wax followed by PVA release agent. The problem is that MDF is as strong as paper when you try and release something from it.
Bruce, great job! I am really amazed how you manage to put all the bits together, get the job done, sail, blog about it all, mothcast to boot and probably work for a living and have a family too. You must have a time machine stashed somewhere in that garage of yours! Good on ya mate!
Hi Bruce,
i have build some moulds the same way like you with MDF. Inside the mould i have sprayd a very strong clearcoat normally used for cars. Have you seen the link called “Fotos von Haralds Umbau” on the german website?
Kerem – It’s called 6 hours sleep a night, and I watch very little television. If I do it is pre-recorded and I skip through the ads.
Harald – Your moulds look very good. We used a 2 pack epoxy varnish, but it simply wasn’t good enough. The second one survived a lot better, but it still can’t be used again.
Bruce,
Your moulds should have a better life span if you use a plastic film as the release. I can’t tell you the name of the stuff I’ve used (cause I don’t know, but have gotten two pulls from my moulds (the second of which was cured at temperature) and they are still good for more.
Any tough plastic contact film should do the job. I apply with a heat gun so it conforms to the mould surface. It may pre-release a little but it doesn’t matter as the vacuum will suck it back down (as long as you envelope the MDF). The film may come away when you release the part but the mould surface stays intact.
Cheers.
You can to get MDF moulds to release repeatedly. I had a centreboard mould that with a couple of coats of paint and a lot of polish got 9 or 10 releases without any damage to the mould.
Keep up the good bloggin’!
if you are going to consume moulds the trick would be to laminate them, then use the router to flatten off the flashing.
if you release the moulding first you have to get the edges down to the moulding line while it is all still floppy, too much trouble. you also have to have a way of locating them to glue together straight and untwisted.
Nice Blog and well done on on the other things your doing as well – it is all good for the class!
Multiple pulls from MDF are really not a problem. If you coat the molds with epoxy ( which sinks in really well) you can have a sealed surface that accepts wax and PVA very happily. My IC dagger board molds have built something like 20 parts and are still just fine. If that is too much trouble for you, you can spray the mold with adhesive ( like 3m Super 77) and squeegee down a plastic film. if you use something stretchy, you can get it into all the corners.
Anyway all good fun.
SHC
Steve,
Thanks for the tip, at this stage we are in development / prototyping mode, so we expect each foil to be an evolution of the previous one. Once we want to make more than one design we will be doing as you suggest or cutting from a resin block.
Regards,
Bruce
Hello!
I m building something like MOTH from wood, but i would like to buy the foilers, beacuase it is too complicated to do them from wood. How much would cost me to order 3 T foilers ??
Regards, Grega