Re: Coil form

You wrote: 


>	Welcome aboard.
>> The only problem
>>this material has is that no glue/adhesive sticks to it very well,
>>making attachment of coil form ends a little bit more difficult. 
>"Hot Glue guns" work well for attachment to polyethylene. If you get a
>1/2" diameter gun, you can get 1/2" polyethylene rod to use in it, and
>weld with it. (U.S. sizes, I'm not sure if poly rod and glue guns
>match up in the UK) The Hot glue does stick to the polyethylene, but
>can be removed with some scraping. Hot glue is not permanent on poly,
>but does hold fairly well.
>	cheers,
>	jim

In building my variable TC capacitors, I use high density 40 mil 
polyethylene HDPE sheet glued with low density polyethylene LDPE.  Hot 
gun glue is LDPE.  The melting temperature of LDPE is lower than HDPE.  
I use two methods of gluing.  In the first, I glue two pieces of HDPE 
together with hot glue.  I then role them together (an ink bray works 
nicely) and apply heat with a model airplane monokoat iron.  The heat 
is adjusted to melt the LDPE and not the HDPE, since I don't want to 
distort the thickness of the HDPE sheet in the capacitor.  The bond is 
excellent.  In fact, if you pull the two pieces of HDPE apart after 
cooling the LDPE remains attached to both pieces of HDPE and tears down 
the center of itself.  In the second method, I am now experimenting on 
larger pieces using a 6 mil LDPE sheet between the two 40 mil HDPE 
sheets and an electric iron.  The temperature is easier to control with 
the iron. 

I am also experimenting using this method to glue HDPE to other 
materials such as aluminum foils.