Boxford Resources System

Dip coating is a simple way to add another finishing process and material to any metal project. The metal needs to be heated up to the point where the plastic sticks to the surface and melts.

With a little practice and a Dip tank you can get this process off to a fine art so that the metal has enough heat for the plastic to stick and then go shiny without smoking or burning.

The dip tank serves its purpose as a fluidised bed. If you look down the tank in the base is a chamber with over 400 holes machined into the top and a vacuum cleaner sized hole in the side. The powder is poured into the top after a suitable additional filter is found (See next paragraph) and the vacuum blows air through the powder causing it to rise and act like a liquid. This ensures that as the hot metal is dipped into the floating powder and even coat sticks to the metal.

All the old cylinder vacuums and some new ones offer the ability to blow rather than suck. Some Wickes workshop Vacuums are versatile and low cost and also have the ability to blow.

The holes need to be covered with something like a vileda cloth which is stuck down before the dip coating powder is put into the top chamber. If you are not sure if the cloth you have chosen is powder tight put a teaspoon of the powder in the middle of the cloth and then pull up the four corners and shake over a sink. If it leaks you need a finer mesh.

Commercial System

Holes

Finally assembly Tips:-

You will notice my style of manufacture throughout many of the Boxford projects this includes:- Size for thickness machining of all holes in wood and fiberboard and size for thickness finger joints with no allowance for cutter diameter. This means that if a piece is to be inserted into a hole the tang will be exactly the same size as the hole and the hole will have radii at the corners. This causes the corners to bind up on the board as it is inserted creating an interference fit that will hold the work whilst the glue dries. Some projects are serviceable on assembly with the glue serving to make the joint permanent.

Powder

The must buy tool you will need to assemble these plans easily is a rubber hammer, they are available from most woodworking suppliers for less then £5.

The hammer will allow you to hit directly on the edge of the board without damaging it as you bang pieces into holes and hammer finger joints together. You may need some cramps to hold some joints but most will hold just on hammering together.

Spanner Dipped

Try to work on opposing sides so that the hammering keeps joints from springing apart the more you do you will find this method of assembly remarkably easy.

You will need a full tub (5kg) of powder to start to give a working powder depth.

And finally the air supply, the powder needs some air to flow through the unit to keep it "fluid" this allows you to push a heated component into the powder without any resistance. The amount of air flowing through the powder is relatively critical but the use of a suck / blow workshop vacuum on the blow side will give more than enough air flow. In fact a certain amount of venting will be needed to stop the powder blowing out of the unit. The effect you are trying to achieve is like a low simmering effect on the surface of the powder. If the powder offers resistance to the hand then the flow is too low. Conversely if there is a haze of powder above the surface or powder is escaping from the unit the flow is too high.

Components need heating to differing levels the thicker the material the lower the temp as the heat will discharge into the powder casing it to stick to the surface, a thicker component will allow thicker coating using the reservoir effect of the components heat loss.

Depending on your choices the finish can be anything from powdery to shinny, to archive shiny there needs to be some residual heat in the component to continue to melt the powder on the surface, if however this does not occur the careful use of a hot air stripper will complete the effect.