Tutorials‎ > ‎Armor Projects‎ > ‎Halo Helmet‎ > ‎

Rondo'ing



What you will need:
  • Automotive Body Filler (We used the Bondo brand)
  • Fiberglass Resin (We used the Bondo brand)
  • 4 Cheap 1" Paint Brush
  • 4 See-through Solo Cups
  • Paint Stirring Stick
  • Protective disposable gloves
Elapsed Time : 7 Hours (Madden and drinking will come in handy)





Okay, so now we have our paper helmet. Don't be disappointed if its flimsy or droopy, we can fix most of that in this stage!

Thanks to a tutorial found here, we were able to successfully make our first Rondo helmet. My previous Fallout 3 Outcast helmet was fiberglassed (such a pain in the ass).

So if you're asking yourself "Self what is the difference between this "Rondo" and fiberglassing?" Im going to be trying my best to explain.

Rondo (A combination of the words Resin and Bondo) is exactly what the name suggests, a 50/50 mixture of fiberglass resin and body filler. This mixture is heavy, not flexible, but significantly easier to apply since it is runny and we can slosh it around the helmet.

Fiberglassing is the application of fiberglass mats along the inside, then dabbing the mats with the fiberglass resin. As the resin dries the mats will become stiff, slightly flexible, and lightweight in comparison to the Rondo. 

We find fiberglassing too time consuming and difficult, so for this tutorial we will be doing Rondo.




Before we can Rondo the inside we must harden the outside with a quick fiberglass resin coat.

The instructions states "10 drops of hardener for every ounce," and it will take roughly 4 ounces of resin to completely coat the helmet. If you dont know what an ounce looks like, take a look at a medicine cup and the 30 ml mark is an ounce.


If you want to be super accurate with your measurement, fill the medicine cup with water and pour it into the clear solo cup 4 times then use a sharpie to mark the level (pour out the water when your done!). Now you can pour the resin into this cup up to the line, and add 40 drops of liquid hardener into the cup. 

Important Note: If you dont apply enough hardener the resin will never completely cure

Grab your stirring stick and mix the batch thoroughly for 20 seconds. Then grab the cheap brush and get a moderate amount of mixture on the brush. 




Now you can start to paint on the resin, but be careful not to over apply the resin we want a nice thin coat. Too much and the paper will warp, too little and the structure wont be strong enough.

*forgot to take pictures of the Halo helmet, we had to substitute our fallout 3 helmet 



If the resin starts to ball up on the paper or get all goopy in the cup, the batch has started to harden and you need to make a new one. We would recommend not trying to continue with the clumpy batch because you will not get and even coat and could ruin the outside. At this point the brush is also hardening so toss it out, but don't worry we have 3 more brushes left.


*Image borrowed from Long Shot's resining tutorial on 405th.com*

Keep applying the resin until the helmet is completely covered.

Now we wait for the resin to dry, this will take 2-4 hours depending on the temperature. Placing the helmet in a warmer area, such as near a furnace, will help speed up the drying process. We would also recommend propping your helmet up on a simple stand made from a board and a dowel.

...Or a broken chair



Lets fast-forward, the resin is completely dried (not sticky to the touch), and its slightly more rigid then before but the panels are still fairly flexible, and able to be popped in.

Its time to don your disposable gloves, and crack open the body filler. We're making RONDO!

Before we start we need to take one of your empty and clean solo cups and fill approximately halfway with the body filler, and the other half with the fiberglass resin, and mix the two parts fully into one solid color. It's okay to mix up a big batch when making Rondo because it takes so much less time to apply it compared to the resin.


For that same reason, I prefer to add extra hardening agent, so the Rondo dries faster, and to ensure that the Rondo cures 100%. I tend to add around 30-40 drops of liquid hardener and about and 1.5"-2" long strip of cream hardener. However you can use only liquid hardener if you prefer.

Now vigorously mix the materials for about 30 seconds, make sure the Rondo turns the color of the cream hardener you poured in. After you mix the Rondo it should have a milkshakeish consistency, but it all depends on how much resin you add (The more resin the more liquidy the material will be).   

*bondo
*Then resin
*Now mix
*Make sure the hardeners are spread completely through the mixture

We are now ready to start pouring the Rondo into the helmet, the best approach is to start by pouring it around the rim, and the hard to reach areas (THE VISOR!!). We like to use our hands to help spread the material around and once the cup is empty we can start to tilt the helmet on every angle letting the Rondo get in every nook and cranny. Note, you definitely want to wear gloves during this phase, the Rondo heats a bit as it dries, and doesn't feel terribly good on your skin. Also, don't wear your watch, and if you want to keep your arm clean, wrapping a piece of plastic cling wrap around it can help.



*cover the entire inside with rondo

Then you can stop and rest the helmet on its top letting the left-over Rondo pool at one side of the helmet. If it seems like there's a lot pooling there, wait until it is starting to cure and become less liquidey, then turn the helmet so the loose rondo works its way onto other areas.

Like This:

Once it dries after 20-30 mins hold it up to the light looking for see-through spots, making mental notes of what needs to be reinforced. We want as little light as possible to be visible through the paper, so this will take more then just one coat.



Whip up and second batch and apply it completely to the inside, like you did with the first batch. Remember back to where you saw the light, rubbing extra rondo in those spots, and this time rest it on another side.

Like so:

Do a third batch, looking over for light and rest the helmet side.

Again, like so:

Repeat this again with the fourth batch, resting it on its last side. *in the case of this helmet, its left side*

We do so many coats to insure that there is a sustainable amount of protection and sanding space, which I will get into in the Bondo stage.

Now take a final inspection of the helmet looking for light coming through. If the panels are are still flimsy and light still comes through you might need one more batch. However if all is well, then you are done Rondo'ing!!!


ALL DONE! now we will add some cosmetic features in the detailing stage.

Previous step, making the helmet using Pepakura. Up next, detailing!
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