Airborne Magazine - Issue #249 | Page 13

tyres fitted I drove out and could see the tyre fitter still trying to tear it off... best of luck mate. I have used it for optical glass joints when I made a couple of underwater camera housings some years back and also for common window glass as a temporary fix after a little breaking accident. For many years I have used it for engineering jobs - gluing metal joints for permanent fixing and every so often for locking bearings in a loose housing (Loctite bearing retainer), collars on shafts and the permanent locking of threaded fixings. A surprise in that field - special lathe and drill cutting tools. Obviously I’ve used it for as many years as it’s been available for model building purposes and, over the years, tried and tested many different brands. For general carpentry work it’s ideal for many jobs but you need to understand what is required before the joining is attempted and this knowledge can be carried over onto the modelling bench. I’m sure you’ve heard that some woods and plywoods don’t glue well with Ca. It is not the adhesive that presents the problem, it is the preparation of the joint that causes the failure. Some woods are difficult to glue with any adhesive and the problem is much akin to aluminium. Cleaned aluminium surface oxidises as quick as you clean it - that is why it is not so easy to solder with normal solder and flux. In the timber workshop, one example is red cedar. You cut it, plane it and leave it for later assembly when all the other parts are ready. When it comes to the gluing with any glue - you are not going to have great success as the surface of the cedar has oxidised rapidly, just like aluminium. It is a case of prepare it, have all parts ready, sand the surface and immediately apply the chosen adhesive. There are several other timbers that have similar problems but these are due to the presence of sap or timber oil exuding out on the fresh surface. Those exudations are one problem but they bring another problem with them - the airborne dust that settles on and clings to the sap/oil and, woodwork shops generally do have a fair bit of dust floating around. The next problem is the surface finish and here we lump in plywood as it is a great offender in this field. Similar to the cedar example - all timbers release resin or wax which lays on the surface and collects dust. As an example of this, using a piece of cut timber that has been lying around for a while but still appears clean on the surface, deposit a small drop of white glue on it. The glue remains in a ball tucked in at the base. It sits on the dust and resin. Sand the surface of a similar piece of timber and wipe it over and do the drop deposit thing with it. The white glue Very handy product for all cyano jobs but - use it wisely and remember it will set off ALL your cyano - even in the bottle. will spread out rather than remain in a ball. If you put a drop of Ca. on the dusty timber it will react with the surface dust and change to a solid coating. This is the reason why ‘instant glues’ appear to be ineffective on some timber joints. General grade plywood is a real serial offender as it has a resinous surface, dust