KiwiDoc's fibreglass TARDIS experiment

[kiwidoc]

So I gave up my scrap timber TARDIS build when I realised it was always going to be too rough and warped to make me happy plus I really wasn't sure that the timber would last outside in my garden for years so my thoughts returned to fibreglass.

For years I've wanted to build a GRP box, following the footsteps of Karsten back years ago (2003/4/5?) and using a door mould to create enough panels for each side.

I have played with fibreglass a bit - I've made a full GRP NS Dalek but there was a lot of trial and error (and expensive wastage!)  I still had some materials though so figured it was worth a go.

I decided to go for NST dimensions, partly as a challenge and partly because it's now seen as 'the' standard TARDIS look to most modern eyes.

Working out dimensions (!) I build a mould from MDF and timber.  Rather than build a door then take a mould from that I thought I'd shortcut and go straight for the negative image so that all pulls from the mould would be ready to go door/wall panels.

Starting with a big rectangle of door height and width, I use ply so that it might have a wood grain.

Took quite a bit of maths to figure it all out but I got there in the end, bought supplies and cut the pieces to shape.  Getting the angle in the panel sides was easier than expected though once again a bit of head-scratching first to make sure I had my figures right!  The panels were not deep enough with the ply I had so I cut the panels in MDF and then stuck a rectangle of Ply on top so that wood grain will show through.  The ply was only 7mm so I added bars of thick MDF underneath it for stength.  These also serve as feet so that the sides can fold down and make the mould easy to move without dragging on the ground.

Spacing and glueing the panels to the main rectangle, I then build hinged sides on all four sides.  These would provide the sides of the doors when glassed against and then flip door when unlocked so that I could pry the door from the mould withouht too much trouble.   This worked well.  Not much else did...

I used MDF so knew it would be porous.  To counter this I painted the mould with paint (yellow) and waxed it with several coats of wax before applying Gelcoat.

I thought it all went pretty went.   The actual application of he fibreglass was tedious, hot and smelly but I got there in the end.  Once it had set I pried it out of the mould and found it had stuck a little in a couple of places.  And a few corners of the panels tore off.  And some of the paint.  And there was triping / rippling throughout the panel, and some of the matting had pulled away in corners leaving gaps or undefined areas...  ARGH!!!!   Insert curse words of choice here.  Sigh...

I really thought about chucking it in, but felt like I'd come so close.   I sanded down the mould, painted again, waxed again, repaired the splinters and tried again.  Used thinner glass mat.  Good.  Used two coats of Gelcoat (I was cheap the first time and thought one would do), took my time and ARGHH - saw the gelcoat ripping even as it dried.  A couple of tears, triping even worse, but corners and detail came out much better than version 1.

Still nasty though.  I can't face filling and sanding the hundreds of issues on these panels so I've decided that I'm not cut out for GRP.  I don't have the right gear (I'm using paint-brushes to apply it), I'm not patient enough and it's pretty expensive stuff to get wrong.  I'm better with wood so my next version is going to be good ole' wood but I have a few twists in mind...

I'm still quite proud of my negative mould and will store it away in case I ever get tempted to try again but otherwise this was a wash out.  I now also have two door panels that I'll store though it might be quite some time until I feel like fixing them up, if ever.

Thanks for reading!  Glen


PS:  Photos follow and should be in chronological order but if any questions, ask away!!

[DoctorWho8]

You should seek out old friend Purple and ask his advice since he's worked with fiberglass pretty much all his professional life.
Bill "the Doctor" Rudloff

[atomicgraph]

hey glen i wouldn't call it a wash i think you've created a great antique looking door. as far as the grp goes looks like a lot of the issues are with the gel coat, and the release. if you coated the mould with a floor concrete epoxy first it'll all pull out easier and it really seals the pores in the wood and mdf. its expensive ($70 a gallon) but it goes along way with using it as sealer. you can also cut out the gel coat but you may want to double up on the matting layers for strength if you give it another shot. good luck

[galacticprobe]

A friend of mine is a professional model-maker who's worked on several of the 'Trek' films and series (from TNG on to at least ST:VI), "Hunt for Red October", and does lots of scale work for military aircraft wind tunnel testing and vessel hull hydrodynamic testing. He's also appeared on some History Channel documentaries, having built RC models of US Civil War ships.

As he says, his biggest secret is that he keeps no secrets - if he learns a trick he'll tell other model makers. His mould release of choice is Pam Cooking Spray. He says it's far less expensive than any "Model Mould Release". It's basically made of the same stuff and works just as well (and is certified to be non-toxic ).

Dino.

[atomicgraph]

Pam cooking spray? I'm gonna give that a try typically I use a wax release followed by pva mould release. The wax is pretty cheap but a lot of work to apply. Pva works the best because it leaves a film but it's pretty expensive at about 10 for less than 12 oz. The cooking spray sounds like a great alternative

[anson]

Looks like you gelcoat is reacting with the paint you used.

[skeev]

Ive done a LOT of fiberglass work and a lot of bulk time sensitive work.

There are a few ways to get the job done.

A couple of things I did.

Mixed the gel coat and the resin for matting using a pedestal drill - if that's not possible - go the other way around an clamp the tin or mixing bowl and use a hand drill with vary speed scoop to mix up lots of stuff quickly.

Mix the gel color closest you can to the end product color.

The gel coat should go on thick - (think peanut butter) with a good quality brush and be done as hard and a quickly as possible - make sure any bubbles are out by pressing hard.

I used wax floor polish for release - makes sure there is plenty on and its rubbed in as good as possible.

The matt or glass fiber should go on only when the gel coat is fingerprint ready - You can leave a mark but it doesnt come off on your finger -  

Only ever one gel coat.

Soak the matt in resin before applying to the surface.

The more layers you put on the better the job - but not all at once - allow some tackiness and steeling before the next layers.

For a Tardis side I would say six layers.

Now Im thinking of a job that will last years - not a thin easily damaged product.

Ive done wholecar body side with intricate angle down to tiny models you can hold in your hand - all involve the same level of commitment and belief that it can be done - if you are worried  - start on smaller parts and work up to sides.

I hope this has been some help - you can always contact me if you want to know more - as can anyone else.

: )

[impact1]

I have to agree with atomicgraph, use epoxy paint to seal the wood. You are defiantly getting a weird reaction to the paint.

If you try another go. I did do some large fiberglass projects a few years back. And for those I needed to stabilize the gel coat, as I was laying up into silicon and vacuum formed plastic molds. To do so I used a mix of 50% gel coat, 25% normal resin, and 25% Bondo, by volume. Bondo itself is just resin and talc powder. but it's much easier to use Bondo then mix dry powder in to resin.

My other advice would be to add reinforcement struts to the pulls before removing them from the mold. After the second coat of glass resin in some wood strips and back with glass.

Good luck.