Hints and Tips

The Gibbins guide

This has to be at the top of the list.

For those who fly electric and have gone on to use lipo batteries be very careful.
I attach a photo of a battery of mine that caught fire whilst charging. The battery was of 2amp capacity and was being charged at 2 amps (1C)
It was on my workbench and as a habit I have always placed the batteries being charged on an old plate which then sits above an old bowl thus giving clearance underneath. All around the battery I also ensure that there is nothing flammable within 18 inches.
I had left 2 batteries charging on different chargers and went indoors to have a cup of coffee and read the paper for 20 minutes.
I heard a pop and a few minutes later could smell electrical burning.
The result was as you can see. Fortunately my precautions were successful in that the fire from a burning lipo only lasts for a few seconds and no fire damage was noticed, there was however a to of black sticky soot all over the workshop that took some cleaning.
Why did it catch fire? I will never know but I had been having some problems with that particular charger recently. The meter indicated 2 amps when I left it which is the recommended charge rate so I can add no more.
The moral is that you must treat lipo batteries very carefully and if possible charge them outside but always on a plate of some sort.

Tip 1

How to determine the centre line of a trailing edge for sanding.
Hold a ballpoint pen between two fingers and use the fingers either side of the balsa to make a mark. Sand to the mark from either side.

This works very well on a curved trailing edge.

Tip 2

For sanding rounded fuselages, wing surfaces etc I now get course sandpaper on a roll about 6" wide. Cut a length and with the fuselage or wing suitably held, just hold the length of sandpaper between both hands and move back and forth across the surface. This gives you very nice rounded corners. You can finish the job by cutting finer sandpaper into strips and doing the same, the length will not be as long.

Tip 3

Still on the subject of sandpaper, I have often used the foam sanding blocks from B&Q etc but for the last year I have bought the sanding pads from Halfords. These are thin foam about 1/4 inch thick and come in packs of two with fine and coarse grades. These fit in the hand so comfortably and follow all contours. Very useful while new but even better when they are worn out. They work brilliantly at cleaning up the soldering iron. Get the iron hot and a quick wipe over the pad removes all of the old solder and brings the tip back to bright copper.

Tip 4

For all users of dope( the cellulose type). For years I have had to throw away brushes after a doping session because no matter how well you try to clean them they always seem to set hard. Flexing the bristles does break up the dope and standing in thinners softens them to some extent but the bristles then come out onto the work in hand. I bought a 1/2" synthetic brush for some decorating at home but when I wanted a brush for doping I had run put of the cheap throwaway ones so used the synthetic one. Almost perfect, one flex of the bristles after use and another next day when dry and the dope just falls off.

Tip 5

I don’t own a razor saw, well I do but I have not used it for years. Instead I use a junior hacksaw in its frame with the blade set to cut towards yourself for cutting straight lines in balsa and ply.
I have expanded the usefulness of the blades by removing the locating pin from the end and then filing a chamfer on the back of the blade to create a point as in the photo.

I find this most useful when cutting slots for hinges in trailing edges etc. Just use a scalpel to cut through the spar then insert the point of the hacksaw blade and saw the slot to length. It is easier to keep straight than the scalpel blade and gives a slot slightly wider than the scalpel. Hinges then easily slot in.
I also use a similar procedure to cut hatches for batteries etc.

Tip 6

As I nearly always build from plans it was difficult to find a piece of clear plastic to protect the plan. You had usually thrown away that old piece last week.
When I worked in the food industry I got hold of an end of roll industrial cling film about 16” wide. I don’t know how this compares with household cling film but it is thicker and works very well to protect the plan. The other advantage is that superglue does not stick to it.
Another source may be farmers that use it for wrapping bales.

Phil's File

Tip 7

Engine turning on Flair round aly cowls or AluClad. Use a Dremel with the bristle brush tool. Smear the target area with the fine grinding paste we used to use on car engine valves in the days when we could still understand what goes on under the bonnet. Then carefully dab the brush onto the aly for a moment, then move on and dab again. I found holding the work close to my chest worked best, but I then had to wash my overall. John Gibbins says toothpaste works as well.