Wednesday, September 1, 2010

Carve Your Own Utility Hat Block

I have an extremely large head--my head size plus big hair equals extremely large head.  All I'll say is that my largest utility hat block is a size 24.  I pad this 24 with felt to increase its size, or I'll stretch the finished hat with a hat stretcher.  I wanted a block specifically dedicated to my head size; so, I decided to carve one.  I prefer to save my money for more exciting purchases like the block below, my latest acquisition.  Now that's a hat block!  Sorry, I'll get back to the purpose of this post--teaching you how I carve a utility hat block.

Carving a hat block is pretty simple.  Many times you will be concerned with creating curves.  In order to create a curve, you would cut your foam or wood edges diagonally; at least that's how I start.  When one edge is cut, you are left with two edges, these two edges are also diagonally cut, forming more edges and those edges are cut, and so on and on.  This is demonstrated in the image above.

I purchased a large Styrofoam cube and scored an "X" on the top and bottom of it (a line from corner to corner), dividing the  foam into equal sections.  I traced my size 24 head size plate onto paper and added 1/8" inch to the traced pattern.  Adding 1/8" to your pattern equals 1/2" to your head size; 1/4" equals one inch, and so on. Unfortunately, this 17" x 17" cube was not large enough for my head size.  I'll get back to this fact later.  The pattern is moved to the bottom of the cube without turning the pattern over.  So, under the bottom of the cube, after moving the pattern down, you will not see the pencil markings on the pattern, but you will be able to see them slightly through the paper because you did not flip the paper over.  These two tracings should be in the same position on top of the cube, as well as on the bottom side.

 Using two straight-edged knives--a large one for mass carving and a small one for detail carving--I removed the excess foam.  My next step was to sand the foam with medium sandpaper.  Always wipe dust from block after sanding.   I applied a lite coat of wood filler and let it dry.  After the filler dried, I sanded the block again.  I applied another coat of sealer, but this time the coat was much thicker.  Remember I said that the foam was not wide enough to accommodate my head size and that 1/8" would increase the block size by 1/2 inch.  Well, the second coat of sealer was a thicker one that also added girth to the block.  This was followed with another sanding.

After letting the filler dry, I added some acrylic paint to some white glue for color.  I added the glue for extra protection and to give the block a softer, springier feel--nice to pin into .  This was followed by two coats of  polyurethane, letting each coat dry before adding another.  Overkill; yes.  I could have stopped after I carved the block, providing it was the correct head size,  but the block would not last as long without some type of protection.  I could have painted on the white glue and nothing else.  I could have used paper mache.  Experiment.  I also like adding the polyurethane because I don't have to worry about heat.  These blocks, when protected with some type of covering, are just as durable as a balsa wood hat block and the cost is much less than a balsa block.

Try carving other shapes and other materials.  To your right is a block I carved in wood with three interchangeable tip.  I learned a big lesson when I carved this block.  I learned not to carve the block on the trace line, but to carve outside of the line.  Sawing or carving on the line reduces the head size, and sanding further reduces it.

Two notes concerning this finished block:

1.  If you click on the image to your left to enlarge the image, you will notice that the block is in profile.  There is actually a bump on the back of the block, as on the back of the head.

2.  In order to get a finer grain on your block, use better sandpaper than I did.  I used old sandpaper because I didn't want to go out to purchase more.

Don't forget to mark the front and back of your block; there is a difference unless you use a round headsize collar rather than an oval as I did.

Always use a dust respirator when sanding wood and  foam.

Always measure your block from top to bottom when carving and sanding to maintain consistent measurements.

Don't forget to coat the bottom of the block with a sealer also.

A more economical material to use for block carving is the sheet foam house insulation.  However, I personally prefer the regular craft Styrofoam, not the soft flower foam.

Remember that an extra one fourth of an inch will add one half of an inch to the head size of a block.

Also, try carving fancier shapes; doing so could mean that your hats would not look like all the others'.  It's really easy.  Enjoy!!

 Check out the two videos below.

Styrofoam Hat block from Al Ojeda on Vimeo.


  1. Perdone que no escriba en su idioma.

    Estaba intentando hacerme, hormas de sombrero con espumas de poliuretano.
    Aprendo muchísimo con su blog.

  2. Gracias. Me alegro de que mi blog puede ayudar a aquellos que, como sombreros.

  3. Thank you for posting this tutorial.

  4. Thank you. I enjoyed putting this together for you.

  5. Just took my first workshop on blocking a cloche and am SO hooked..Thanks for providing further insight into DIY blocks!

  6. I'm glad you're hooked. Don't think you're odd when you start seeing a hat or hat block in almost everything you come across :)

  7. Hi Lee,
    I enjoyed reading your blog posts as I recently carved my own styrofoam blocks for my big head and big hair! Glad I'm not alone in this :) I've been wanting to get myself some blocks to use once my course ends but they are so pricey... I was interested to find out more about Fosshape, I'm hoping I can find some to play with over here in the UK. Looking forward to reading more on your blog! Towera

  8. Towera,

    Forgive me for taking so long to reply. About Fosshape, it is excellent to create a shape then stiffen it or paper mache it as I did because heat makes it soft. It is wonderul if used in this way.

  9. Hi Lee,

    Thank you for the lesson.
    What about people like me how don't have a block to trace from, what can i do to get the right diameter?
    Please help!

  10. Hi Malik,

    Thanks for the question. Actually no one's head is a perfect oval. So, if you need to create a head size template for yourself, a flexible ruler would be perfect. You can measure around your head and lift the ruler off, and make a tracing.

    If you have millinery wire (or sturdy craft wire), wrap it around your head, remove it from your head, and secure the wire with tie wire, thread, or a wire joiner. Then roll the wire back and forth between the palms of your hands, thus shaping the wire in the hand.

    From the suggestions above, trace in the inside of your wire or ruler shape, thus creating your own head size template.

    You can also purchase these head size collars. Also, there are other ways of creating these templates, but I don't want to go into the mathematics of it all.

    Hope this helps,


  11. Thank you so much for all the information you are sharing with us! You're a great woman!

  12. Thank you Georgia for taking the time to leave a massage. I hope you find more here that you find helpful.


  13. Thanks so much for sharing your knowledge and for this particular post especially. I'd been wondering if paper mache would work and this idea seems much better.