Put Put or Pop pop boat is a classic toy from my childhood and never understood why it was called put put boat, until recently.

There was a school project ( neighbor's Son ) on "Heat conversions usage" and this pop pop boat spring in my mind. I did quit some reading on intructables and Google. Most of the methods failed for me. In this instructable I will share what I did wrong and what could have I prevented to avoid it

Step 1: Material and Tools

As I mentioned, most of the items we are going to use are wastes

Pepsi / coke Cans
Straws 2
Milk Cartons 2
Candle / tea Light

Hand Tools

Nose pliers
Scissors
Cutter
Silicone Sealant
Acrylic paint
Paint Brush
Sanding paper

Step 2: Boiler

Warning : While cutting aluminium cans, one must be extra careful. The left over/ wastes are very sharp and must be disposed with alot a care

We need to make a pocket / envelope like box. I used a thinner aluminium can, So I got two side build without any leaks. Use Silicone sealant to seal the other two sides as shown

Cut a small opening on one of the sides and insert the two straws and seal it.

Test for leaks by submerging into water glass and blowing air through straws. If you see bubbles, try to seal it or start over.

This is the heart of the boat and most of the time single point of failure. So making 2 or more boilers will help

Problem 1 : Boiler Leaks

M Seal/ Blue Tag : cannot seal the leaks properly, all attempts will fail

PVC adhesive : Seals all leaks, but as soon as to introduce heat, it melts and results into leaks

Silicone Sealant : Seals all leaks and heat resistant. bit messy to work with. Apply oil on your hands before working

Step 3: Boat

Now for the boat, I used empty milk cartons and very simple design.

It is important that we pass the straws through the boat, this part will be touching water, so allows quick cooling of heated water from boiler.

The straws should be secured with the base of the boat so that we can get good thrust

Step 4: Paint and Test

Paint it using Acrylic water proof colors. Test it in control environment. Adjust the flame height

Problem 2 : Boiler does not get hot

Raise the height for candle or add more candles to heat. I used Camphor which melted my PVC adhesive in 2 minutes

Problem 3 : Boiler is at angle, so candles / tea lights are not effective.

What we can use is another set of bendable straws and make a U. This also introduces a leak point, but we should be able to seal it using PVC adhesive or Silicone