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Hirst Arts Moulds

It's taken me an awful long time to write this review of Hirst Arts' moulds.

The Tomb The Wizards Tower

A Fieldstone DungeonThe first problem was that simply saying "they're great, go buy some" seemed a bit on the short side while a detailed description of how to use them would also be pointless considering the wealth of information on Hirst Arts own website. In the end I decided to describe my own experience of using them however the problems didn't stop there because although I was the proud owner of six Hirsts Arts' moulds when I began this review, as I do the final editing (read total re-write), my collection has grown to no less than fourteen moulds. Indeed the image to the right uses blocks from three of the Hirst Arts' Fieldstone moulds plus accessory moulds from the Gothic, Egyptian, and Cavern ranges.

Of course you don't need that many moulds to do something useful. Take the accessories out of that dungeon and create your own castle clutter and you only need two Fieldstone moulds (one for the floor and one for the walls) to construct a basic Fieldstone Dungeon. The Tomb and The Wizards Tower in the images above can each be made from a single mould and while not all of the moulds are equally versatile, by the time you get to the end of this review you ought to be in a position to make a buying choice that's appropriate to your skills and budget.</p>

So let's get under way with a quick look at the first six moulds that I obtained from Hirst Arts and which form the backbone of this review:

My first six Hirst Arts moulds

From top left to bottom right they are:

#50 - Wizards Tower
Recommended by Hirst Arts as being a good place for the beginner to start.

#100 - Basic Block Small Mould
The same blocks as are used in the Wizards tower and therefore useful if you want lots of these blocks for other projects.

#56 - The Tomb Mould
I just fell in love with this piece and what's more the pieces can be used to dress up structures made with the two moulds above.

#260 - Flagstone Floor Tile Mould
#70 - Fieldstone Wall Mould
The 'basic' requirements for making fieldstone dungeon pieces - something else that I fell in love with and want to use to make terrain for my <a href="http://www.escapepath.com">EscapePath</a> project.

#71 - Fieldstone Accessories Mould

One of a number of enhancement moulds that are available to accompany the fieldstone blocks.

First Impressions / Quality

I don't know why, but when I first got my hands on the moulds I was surprised by their compactness and had expected them to be larger. This is not a criticism; it just surprised me. The moulds listed above vary in thickness from 1/2" to 7/8". The smallest (#100) is 3" x 4" while the largest (#56) is 4.25" x 8". The other four are 4.5" x 4". The interesting thing to note here is that all of the moulds are arranged such that a 4" wallpaper scraper can be used to scrape them (more on this later).

As for the quality, I can't fault it. These things are absolutely spot on. Flexible enough that you just know it'll be easy to get the casts out and sturdy enough, with ample wall thickness, that you have no worries about them flexing when you pour the plaster.

Other Things You Will Need:

Of course you'll need a few other items and although I'm not going to list them all (read the instructions at Hirst Arts) I would like to make a few comments:

Hirst Arts suggest buying disposable plastic drinking cups in which to mix plaster. I'd go with that for starters but if you get into this I'd seriously consider a flexible mixing bowl.

Hirst Arts MouldsThere are two methods for getting a flat top to the plaster after pouring it into the mould (see Hirst Arts site). One employs a sheet of glass. If you go for this option then for goodness sake make sure it has no sharp edges. The glass from an old/cheap picture frame was never meant to be handled and will probably be sharp. I opted for the second method which employs a 4" wide wallpaper scraper; purchased especially for the job from a discount store at the enormous expense of 70p (about $1 US).

Hirst Arts site describes the use of a rinsing agent i.e. the stuff you use when washing dishes, or rather when rinsing them, to prevent water marks. This is used to make 'wet water' into which the moulds are immersed prior to pouring the plaster. Hirst Arts site gives the impression that this is 'optional' but I reckon I'd be pretty cross if I found myself wasting time and plaster, on bad casts for the sake of saving a quid on a bottle of rinsing agent that'll last for months if not years.

Another thing to put on your shopping list is a pack of paper kitchen towels. You'll probably use lots of these so unless you actually enjoy getting grief from the rest of the family for having used up all the towels in the kitchen, go buy some of your own. Pretty flower patterns down the edges are optional.

While you're at the supermarket get yourself some talcum powder because you'll need to dust the moulds with it (it stops them sticking together), when you've done casting and come to store them.

Of course you will also need casting plaster. Check out my review of Keramin to see what I use and why.

The final thing I want to mention is PVA glue. Bruce Hirst states a preference for "Aleen's Tacky Glue" but I like PVA. I've done a few tests where I've stuck blocks together, let them dry and then snapped them apart. I CAN snap them apart but it takes a LOT more force than any terrain piece should ever encounter.

Preparation, Mixing & Pouring

Most of what you need to know about mixing and pouring the plaster is already covered in our article about working with plaster so I won't repeat it here. However I would like to remind you to wash the moulds and immerse them in 'wet water' prior to each use, to dislodge bubbles. The initial washing is also necessary to remove talcum powder that was applied to stop them sticking together during storage/transit. When you're done using them and want to store your moulds you should dust them with talc for the same reason.

In each of the moulds there are some pieces that will cause you more problems with trapped air than others. The instructions at Hirst Arts give some pointers however you'll quickly get to know which are the tricky pieces on any given mould and can then take various extra precautions:

Hirst Arts Moulds Hirst Arts Moulds

In the images above I'm using a brush to place plaster exactly where I want it. Notice how I'm bending the mould to stretch open the problematic piece that I want to fill.

In the first of the images below you see me using a cocktail stick to make sure there are no bubbles lurking in the corners of another piece that I know to be a source of trouble.

Hirst Arts Moulds Hirst Arts Moulds

The last of the images above shows me using the brush to push a 'wave' of plaster along another problematic piece. I've used the brush to place plaster into the centre of that piece and in the image I'm pushing it towards the end so I can keep a close eye on the corners to make sure no bubbles get trapped. Shortly after this picture was taken the bubble that you see in the centre of one of the pieces that I'd already filled, died horribly on the end of the aforementioned cocktail stick.


When pouring, the moulds are filled such that the level of the plaster is above the top of the mould. Hirst Arts suggest leaving the mould for 6 minutes before scraping off the excess but this is going to vary. The first time I tried it I found that the plaster was 'dragging' - because it was still too wet. I left it another minute, still too wet. Another minute, just right. As I said it will vary so you need to try it and if it's too wet go back and try it again later. It's important that the finished blocks are as level as possible so that they stack properly when you come to build with them. You won't get it perfect, but you should give it your best shot.

Hirst Arts MouldsThere's a knack to the scraping so here are a few tips:

  1. Be gentle. The moulds are soft silicone. If you press down even slightly then you will press into the silicone and remove plaster from below the surface.

  2. Work slowly such that any plaster that 'drags' but should really remain in the mould has chance to settle back into the mould. If you move too quickly you'll create a 'wave' of plaster and remove more than you should.

  3. Hold the scraper at an angle as opposed to having it vertical as this will help to prevent drag.

  4. Run the blade of the scraper such that it meets the edges of the holes in the mould at an angle as opposed to them being parallel. Of course if you are not exerting any downward pressure at all then the blade won't 'snag' when it meets an edge, however the reality is that you will be exerting a tiny amount of pressure and meeting those edges at an angle will help to prevent snagging.


Hirst Arts MouldsI can't promise that you'll experience this, but for me there's a certain inexplicable joy that comes from 'popping' the finished blocks out of their moulds. They won't fall out but flexing the mould will release them such that you can pluck them out. If you're the kind of person who eats peanuts one at a time then you're going to love this whereas if you're a shovel them in by the handful kind of guy then you probably won't get it.

Don't be tempted to strip the mould too soon. When you scrape the moulds you will end up with some excess plaster on the side of them which can be used as an indicator of how the plaster in the mould is setting up - but bear in mind that this excess will probably set a bit faster than the stuff in the mould.

If you do try to release them too early, the most likely result is that a piece will snap. If that happens leave the mould for a while longer before attempting to remove any more pieces. As for the broken piece, you should have no problem mending it with PVA glue AFTER it has been dried out.

Construction & Painting

Hirst Arts MouldsAlthough I'll present some of the main points here I'm also going to provide you with links to three sub-reviews that follow three different projects and give a lot of additional information:

  1. The Wizzard's Tower
  2. The Tomb
  3. The Fieldstone Dungeon

The image to the right show the early stages of my version (no floor) of the Wizard's Tower. Note that I've been using Lego bricks to assist with the alignment. This is suggested in Bruce Hirst's instructions and I thoroughly recommend it. If you don't already own some Lego bricks (shame on you) then you can easily buy a handful of suitable blocks on eBay. No arguments, just do it.

Another thing to note is that I'm using PVA. I've watered it down slightly and this allows me to apply a couple of drops where a block is to be placed and then, when it's in place, add a drop of glue to the joints between that block and any others that it's touching. Capillary action draws the runny PVA into the joints and the job's a good one.

A final point worth mentioning is that I'm working on a Citadel Paint Station. You'll need to construct your model a few courses of blocks at a time and in between session you need to move it safely out of the way where it won't get knocked.


I suggested right at the start that you should just go buy some and I'm not going to deviate from that. Well not by much.

My version of The Tomb from Hirst ArtsThe thing is that once you've tried them you'll either find that:

a) you just love casting those little blocks and can't wait for the family to go out again so you can claim the kitchen, put on your desert island discs, and cast away (pun intended - I'm sorry but I couldn't resist).

b) you find the casting a bit boring but can tolerate it because the end results are worth it.

c) the casting process numbs your mind to that of a zombie and you set out to kill Bruce Hirst for making the moulds and me for recommending that you buy some.

It's really difficult to predict. You might think it'll bore you senseless (actually you probably wouldn't have read this far if you anticipated that), and find that popping those little blocks out of the mould fills you with delight. Then again you might think you'll be cool with it and find that it drives you insane. The moulds themselves are excellent and I'd recommend that any terrain maker who's even slightly impressed by the models on Hirst Arts' website should give them a try.

Hirst Arts Fieldstone Dungeon with Cavern AccessoriesSo, assuming that you are in the market for some moulds, what should you buy?

Well obviously it depends to a large extent on what takes your fancy however:

Some moulds are more prone to trapping air (THE big issue when casting) than others. The more intricate the details, the more chances of trapped air, and the more it will matter. For example you are less likely to get trapped air on a fieldstone wall block than you are on a Gothic gargoyle and while a bubble on a fieldstone wall will probably go unnoticed, a bubble that takes the nose off a gargoyle will probably make it unusable. Fieldstone is also relatively easy to patch up with filler while smooth blocks such as the Starship blocks and textured blocks such as the Egyptian blocks are harder because it's harder to match the filler with what's already there.

Some moulds are also more versatile than others. The Wizard's Tower mould for example has lots of plain blocks that can be used for lots of different projects, while the fancy and rather specialised pieces in The Tomb mould are significantly less useful for making anything other than "The Tomb".

Hirst Arts Moulds

My Ork Bar uses Fieldstone blocks for the stairs but the wall is foamSomething else to bear in mind is that while in some cases the moulds really are the best way to make something, there are other cases where I feel that the moulds have been produced for the benefit of those who love casting and hate using foamcore, plasticard, or in fact any modelling material other than plaster. On my [album=97,Ork Bar] for example I used Hirst Arts' blocks for the stairs but made the wall behind them by drawing the same pattern onto a sheet of polystyrene foam. It would have taken an awful long time to cast the number of blocks I'd have needed for that wall. On the other hand, I have found with my dungeon, that part that makes me think "Oh no, time to do that again", is drawing the fieldstone pattern onto the foam foundations. Oh how I wish I could cast them instead.

Hirst Arts MouldsHirst Arts suggest The Wizards Tower as a good starting point for a beginner and if their Gothic range appeals to you then I'd agree. However, although The Wizard's Tower is relatively easy to cast, The Tomb (another Gothic mould) is quite a bit harder and one of the most difficult moulds, to get bubble free casts from, that I've used to date is mould #43 Gothic Panel Accessories.

Personally, I would suggest that if you like the Fieldstone stuff, then go for that instead. It's very forgiving on the bubbles problem and very versatile. Since I began writing this review I've amassed a collection of some 14 Hirst Arts moulds, and borrowed another couple from a mate along the way, and the Fieldstone moulds are my favourites of the whole bunch.

Mould #70 (Fieldstone Wall) and #260 (Flagstone) are probably the most versatile Fieldstone moulds but if you can only justify/afford buying one, then check out mould #74 (Fieldstone Bridge) as this has 'a bit of everything'. Also, particularly if you're interested in making small ruined pieces, take a good look at #75 (Ruined Fieldstone) because although it appears at first glance to contain nothing but ruined blocks, they have been cleverly designed to fit together so you can make whole blocks, whole flagstones, and arches from the ruined bits.

Overgrown ruins using Hirst Arts blocksIf you're more inclined towards one of the other ranges, all I can really suggest is that you think in terms of what is likely to prove most useful and lean towards the simpler 'basic' moulds than the ones that are loaded with 'accessories'.

For more information about the moulds, check out Hirst Arts' website at http://www.hirstarts.com.

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