coil shiellding

[kt315]

I have tried PVA and graphite but never had any luck.

try use a bitumen varnish with graphite

[mohandes]

hi
can use this model for 110*110cm coil?

[CAS]

While this is a pva base, I am not sure its the same as PVA glues. What I did was put some of the agent in a container, mixed in enough graphite to make a stiff paste and then just watered it down a little to the constancy of a thick paint. I think painting it on to the adhesive bandage allows it to soak in to the fibers allowing it to stay very flexible. It certainly doesnt scrape off the bandage and because I thread the wire into the bandage as though it were being sewn in, it wont come out and forms a good bond.

[Koala]

My original test strip dried to a resistance of less than 300 ohms while still retaining flexibility. I have now coated a Litz wire coil and I am pretty happy with the result. I left 2 x 1200mm Litz tails from the coil and threaded these through a length of coax from which I had removed the center core (just leaving the shield). This way there is no soldering at the coil. I then threaded the end of the shield through a section of the tape I had wound around the coil. Then I coated with the graphite mix and left to dry for a week. I tried to pull the shield wire out but it is stuck fast with a great electrical bond. Its only a 6" coil and am now going to try it on a 14" coil.

How much mortar bonding agent to graphite

When I tried PVA it ended up too brittle and the tap wire would pull out and the coating was too easy to scrape off

[CAS]

My original test strip dried to a resistance of less than 300 ohms while still retaining flexibility. I have now coated a Litz wire coil and I am pretty happy with the result. I left 2 x 1200mm Litz tails from the coil and threaded these through a length of coax from which I had removed the center core (just leaving the shield). This way there is no soldering at the coil. I then threaded the end of the shield through a section of the tape I had wound around the coil. Then I coated with the graphite mix and left to dry for a week. I tried to pull the shield wire out but it is stuck fast with a great electrical bond. Its only a 6" coil and am now going to try it on a 14" coil.

[kt315]

oldier suggestion i did read in russian sources for diy conductor is a mix from the graphite and a silver (the powder).

[6666]

I have tried PVA and graphite but never had any luck.

[scrungy_doolittle]

The mortar bonding agent is just PVA i.e. Elmers white glue.

[6666]

Thanks Cas, will check out these products.

[CAS]

Cas would you mind telling us the name of the mortar bonding agent?

and was the tape Elastoplast Sport Elastic Adhesive Bandage 50mmX3m Roll

Thanks

I use the sports tape because it has a stronger adhesion than others I have found while being porous enough to hold the graphite mixture (plus its what I had at the workshop).

[6666]

Cas would you mind telling us the name of the mortar bonding agent?

and was the tape Elastoplast Sport Elastic Adhesive Bandage 50mmX3m Roll

Thanks

[CAS]

Well seeing as I am impatient, I thought I would experiment with what I had on hand and I think I may have a good combination.

I used a mix of graphite powder and a mortar bonding agent (you can get it from hardware stores) and thinned it down with a bit of water. I brushed it on to some sports strapping tape and now have a flexible, conductive piece of tape.


Conductivity between the 2 wires - 60mm apart - is approx 1k (thats only 1 coat - more coats may reduce that resistance if needed)

I will wrap the coil and then brush the graphite coating on. As the mortar bond and tape remain flexible hopefully the shielding shouldnt suffer cracking. it seems to be pretty abrasion resistant too. The small shiny marks are where I tried to scratch it with sharp probe points.

[Koala]

What about old carbon copy sheets?
Is there someone who has tried them?

Normally not carbon but use wax

[Altair]

What about old carbon copy sheets?
Is there someone who has tried them?

[multieagle]

Most autoparts stores, ie Canadian Tire in Canada, carry graphite spray.