Have you ever wondered what it takes to make a mold?

mattw

Active member
So I'm on a mission to have my 4-door cladding done before NATs. In lieu of trying to cut up and glue together stock cladding I've decided to make open face fiberglass molds of a stock cladding set. I will then be able to make fiberglass reproductions of the parts, cut those up, and re-glass them together to make my 4-door cladding..

I'm also hoping I can start selling parts on the side to help fund this project. I'm finding its very expensive and extremely time consuming to make these molds..

Step 1:

The part you want to copy must be in perfect condition. Any imperfections in the original will be transferred to the mold and then to any parts made in that mold. In most cases this means doing body work and priming these pieces of cladding.

Step 2:

Any negative curves on the part must be flanged or plugged. If you don't do this your original will get stuck in the mold and you will never get it out. Also all edges of the part must be flanged. This helps provide rigidity and also makes it much easier to make clean edges on the parts made in the mold.

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Step 3:

All holes must be filled with clay.. This is one of the few steps that actually goes fairly quickly...

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Step 4:

You must wax your original part so that it will not get stuck in the mold. You can't wax it just once though.. It needs to be done 8-10 times and you need to wait at least 1 hour between each coat.

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Step 5:

Next you have to spray down a PVA(release agent).. This is done in several very light mist coats.

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Step 6:

Once your release agent fully dries you can apply your gelcoat. This can be brushed or sprayed. I use a gelcoat cup-gun as you get better results that way. It takes 3-4 coats to get the appropriate thickness. This part is scary.. You feel like you are ruining a perfectly good part.

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Step 7:

Cloth.. Once your gelcoat tacks up, but before it completely dries you need to apply your first layer of cloth.. I use a 6oz cloth for this:

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Step 8:

That first coat needs to completely set up.. So its a good idea to let it sit overnight. Next I do a layer or slightly heavier cloth.

Step 9:

8-10 layers of MAT.. This is a slow process as you need to ensure that the resin completly saturates the MAT.. You have to dab it in with a brush and use rollers to get all of the bubbles out.. It took me just over an hour per layer.

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I think I did about 10 layers..

Step 10:

If you are lucky your original part will release without issue.. I got lucky with this one.. This mold will need to be trimmed, wet sanded, waxed, and then it can be used to make a part.

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This is the 5th mold that I've made.. I don't need to do the rear bumper or support as I have stock parts to run for that. I think I've got about 8-9 molds left to make yet..

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ziembic

Donating Member
Re: Have you ever wondered what it takes to make a mold?

Matt, if you need any parts to use for molds, let me know. I have spares of everything. Two questions I have for you: How does it work when the part has tabs. I see the eye brows have some attachments where the tabs would be, but are they molded as part of the piece? The other question: how do you finish the process by making a new part?
 

Ruddell

Member
Re: Have you ever wondered what it takes to make a mold?

Wholly frick is that some big time stuff. So is the mold that you created need to go through pretty much the same process starting with the gelcoat to make a actual part with it? Thanks for documenting this process its very interesting.
 

mattw

Active member
Re: Have you ever wondered what it takes to make a mold?

Matt, if you need any parts to use for molds, let me know. I have spares of everything. Two questions I have for you: How does it work when the part has tabs. I see the eye brows have some attachments where the tabs would be, but are they molded as part of the piece? The other question: how do you finish the process by making a new part?

Thanks Jeff.. I think I have everything I need but maybe some of your parts are nicer than what I have..

As far as the tabs go I am creating jigs that bolt to the molds. The jigs provide a flat metal surface where the tab should be and I will lay up glass there on the metal.. When the jig is removed I will be left with a fiberglass tab that is glassed right into the rest of the part..

That rear corner has the jig on it as well.. Here is a close up:

http://mattw2.dyndns.org:81/pics/Cl...ear Corner/RH Rear Corner with tab spoort.JPG

Wholly frick is that some big time stuff. So is the mold that you created need to go through pretty much the same process starting with the gelcoat to make a actual part with it? Thanks for documenting this process its very interesting.


You are mostly correct about the finish process.. The good part about it though is its MUCH quicker.. You don't have to worry about flanging anything, that first coat doesn't need to fully cure, and you only need about 3 layers of cloth/MAT.. It took me about 45 min to make a rear arch. Thats the only part I've made so far in the molds.. Hopefully more will be made in the coming weeks..
 

ziembic

Donating Member
Re: Have you ever wondered what it takes to make a mold?

Let me know, I am more than willing to lend them to you. Thanks for the explanation.

Thanks Jeff.. I think I have everything I need but maybe some of your parts are nicer than what I have..

As far as the tabs go I am creating jigs that bolt to the molds. The jigs provide a flat metal surface where the tab should be and I will lay up glass there on the metal.. When the jig is removed I will be left with a fiberglass tab that is glassed right into the rest of the part..

That rear corner has the jig on it as well.. Here is a close up:

http://mattw2.dyndns.org:81/pics/Cl...ear Corner/RH Rear Corner with tab spoort.JPG




You are mostly correct about the finish process.. The good part about it though is its MUCH quicker.. You don't have to worry about flanging anything, that first coat doesn't need to fully cure, and you only need about 3 layers of cloth/MAT.. It took me about 45 min to make a rear arch. Thats the only part I've made so far in the molds.. Hopefully more will be made in the coming weeks..
 

MRKING

New Parts for Old Trucks
Re: Have you ever wondered what it takes to make a mold?

Looking real good Matt . Your doing a great job !!
 

mattw

Active member
Re: Have you ever wondered what it takes to make a mold?

Looking real good Matt . Your doing a great job !!

Thanks.. You know I will be picking your brain @ NATs about this stuff, right..

...


So I trimmed the mold over lunch today and brought it home..

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Its now resting peacefully by my super technical mold curing device....

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The wife hasn't bitched yet about the smell but she is going to be totally pissed when I put it in the bathtub tomorrow to wet sand it.. :)
 

Quickstop [UK]

Combating adversyty.
Re: Have you ever wondered what it takes to make a mold?

Nice - what are the finished pieces set to cost approximately?

Could you convert them to make fibreglass moulds?

I love seeing the work rather than seeing promises :D

:tup:
 

mattw

Active member
Re: Have you ever wondered what it takes to make a mold?

Nice - what are the finished pieces set to cost approximately?

I'm not sure yet.. I know what Paul's Select charges and I don't think their prices are too far off considering the amount of work involved.. I will most likely price below them a bit though.. Also I'm not at all opposed to bringing pieces to NATS and/or regional meets to save on shipping..


[QUOTE='Quickstop [UK];Could you convert them to make fibreglass moulds?[/QUOTE]

They are fiberglass.. Do you mean carbon fiber? If so I "think" so.. Thats one of the things I want to ask MRKING about.. I was also wondering if I could lay up epoxy based parts in polyester molds.. This would be a great way to fix broken cladding..

[QUOTE='Quickstop [UK];I love seeing the work rather than seeing promises :D

:tup:[/QUOTE]

Thanks!
 

It's just a six

Super Member
Re: Have you ever wondered what it takes to make a mold?

Nice work.:tup:

Are you going to vacuum bag the parts or is that possible?
 

MRKING

New Parts for Old Trucks
Re: Have you ever wondered what it takes to make a mold?

Thanks.. You know I will be picking your brain @ NATs about this stuff, right..

...


So I trimmed the mold over lunch today and brought it home..

73_Flanges%20Trimmed.JPG


Its now resting peacefully by my super technical mold curing device....

74_Fully%20Cure%20by%20woodstove.JPG


The wife hasn't bitched yet about the smell but she is going to be totally pissed when I put it in the bathtub tomorrow to wet sand it.. :)
:tup: Pick away , lol .
The post cure is a great way to avoid warping , good thing your wife doesn't mind the odor .If you dont want to use the bathtub , a 5 gallon bucket and some sanding sponges work great . A few drops of dishsoap will also keep the sanding grit from loading up your sand paper/sponge too. You should have no problems with making epoxy parts out of your poly mold as long as you give it a few good coats of wax/polish , and then pva . A step up above that would be semi-permanent releases . Worth looking into for future stuff if you can swing it , some are big $$ in comparison .
 

MySaudi

New member
Re: Have you ever wondered what it takes to make a mold?

looking Great, I like to come on here and read what people can do to make these truck come along. :tup:
 

gobabygo

New member
Re: Have you ever wondered what it takes to make a mold?

Damn good work. I would like to see some of the parts once they are done. Glad to see more cladding available for our trucks.
 

mattw

Active member
Re: Have you ever wondered what it takes to make a mold?

I would like to see some of the parts once they are done.


I made this part quite some time ago before I built the jigs for the tabs.. So its currently tab-less...


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Its the first and only part that I have made so far.. There are some issues with it but nothing major and nothing that can't be fixed when I make future parts.. I intend to run it on my truck..
 

gobabygo

New member
Re: Have you ever wondered what it takes to make a mold?

Good work. I like that there will be more cladding available. If it turns out good and the price is good you will not have any problem selling your parts. I will be in line to try some of them.
 
Re: Have you ever wondered what it takes to make a mold?

Very nice work!

I've read a lot about the process and watched a ton of videos, I just never have the ambition to attack it. Very nice.
 

mattw

Active member
Re: Have you ever wondered what it takes to make a mold?

So I was able to get the front cover mold wetsanded yesterday.. 600 -> 1000 -> 2000 grit..

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I was also able to get a couple coats of wax on my rear corner mold..

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