How Do I Mix Fuel for My String Trimmer, Hedge Trimmer or Chainsaw?

These garden power tools generally have a two stroke engine (also known as a two cycle or 2T engine), and to make them lighter, they don't carry motor oil on board as in the case of a lawn mower or road vehicle. Instead oil is added and mixed with the petrol (gas) before use.
In general petrol/oil ratio for 2-stroke engines is 40:1 or 50:1 which is 2.5% or 2% oil. 50:1 is equivalent to 20ml in 1 litre or just over 2 1/2 US fluid ounces per US gallon. 40:1 is equivalent to 25ml in 1 litre or 3.2 US fluid ounces per US gallon. 
After adding oil, swirl the contents around to ensure it's thoroughly mixed.Consult the manual of the machine for details of the recommended ratio.

How to Stop Nails Splitting Timber

Flat or round nails can split timber, especially if they're used near the edge because the sloped tip acts as a wedge. An old tip is to shear the tips off wire nails to stop them doing this. The nail then shears and cuts through fibres rather than acting as a wedge, pushing them apart and splitting the timber.

Homemade Tools - Snow Rake

I put this together from scrap 2 x 1 and 3/8" (10mm) plywood. I used some pieces of waste wire from electric cable (string would be just as good) as ties to stop the board pulling off the end of the 2 x 1.

New Science Q&A Article for Children

Just published a new science guide for children.

"Top 100 Interesting Science Questions for Kids" covers space, nature, technology, engineering, elementary math, chemistry, physics and biology.