Mel Parker
Member
and were getting ready for paint.
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Repaired another Tornado coil today.....
- Thread starter Mel Parker
- Start date
OldBeechnut
Well-known member
Nice work Mel!! Nice weather is coming, gotta get these babies tuned up!
Mel Parker
Member
Cliff it's pretty straight forward like you said but the secret is in the bonding agent holding the coil and the oval PVC together, you can't break them apart after they are cured. The bonding agent is home made with MEK and pieces of old black PVC coil covers placed in a Nalgene bottle. The MEK melts the PVC coil cover chunks into a thick liquid and you apply it with a syringe. When it cures it becomes one piece and works better than epoxy, It won't beak off if it's bumped against something.
biglry
Member
Yep, I have a Minelab 10" slim line on the bench waiting to fill with epoxy that I started repairing last night. I want to thank Mel for his informative post about making your own MEK based welding glue and the pic of using PVC for the housing 
Took a few times adding pieces from an old coil cover and mixing with an old screw driver to get the consistency and thickness I thought I wanted, you will notice I had some fine strings like spider webs of glue on the PVC, I'm going to thin the mix down before doing this again.
Using a syringe with out the needle was the way to apply with accuracy even the "to thick" mix I used went through the syringe okay and I was really surprised, when the syringe cleaned up real nice the MEK had no effect on it and I can reuse it.
I used a pint mason jar to mix in and kept the lid tight, the fumes will eat the rubber seal on the lid so I was careful to wipe the soft rubber off every time I opened the jar as not to get any in the MEK mix and retightened the lid very hard every time(got to get some of them plastic bottles).
I used a piece of 3/4" pvc formed to the shape I wanted with pair of pliers and heat gun.
The cable I used was the Master Carr's unshielded continues flex, 4 connector #9204k12 recommended by OldBeechnut (thanks).
I've now replaced three Excal coil cables with that stuff and love it, just be sure to mark the ends as it has 3 wires in red and one in a yellow/green. I used a black permanent marker to put stripes on the wires after doing a continuity check so I had matching ones on each end, I also drew up a wiring schematic so I knew which ones were going where on the coil.
Since I was going to completely replace the coil wire by hard wiring the cable to the circuit board I had to remove the old cable and unsolder all the wires going through the end cap to the circuit board, again I drew a schematic of all the wires on the circuit board and cross matched them to the new wire.
Note: I just unsoldered the power wires, but still drew them in the schematic to be sure of the replacement positions.
Always ground yourself when handling and working on the circuit board.
End cap preparation: Be careful using the drill as it can grab the rubber and wires, I pulled the copper wires out first with pliers, then after running a 1/4" drill bit through the end cap to remove what was left of the old cable I took a 3/8" drill and countersunk the inside of the end cap's 1/4" hole about 1/2" deep so I could install a small nylon zip tie around the cable then stuff it into the recess. When done it basically looks just like Minelabs. After installing & tinning the wire ends with solder(I use 60/40 electrical solder) I pulled the cable through the end cap. Next, after putting on the zip tie I pushed it all into the 1/2" deep hole and filled with a fast set plastic two part epoxy made for Plexiglas and acrylic applications, I find it works good and does not effect the cable, but you got to be fast as it is quick to set up, it is also used to glue the back glass to convertible car tops and found in Walmart or most any auto parts store. OldBeechnut may have a better epoxy recommendation for this and I hope he will chime in here, but I have used this stuff and am familiar with its properties.
Note: install all O-rings and slide strain relief and end cap's black cover on cables before you solder all the cable wires (don't ask how I know this).:angry:
Here are a few pic of the job and it will be ready to use in a day or two as it is my backup to my backup Excal
Coil repair set up
MEK on outside
MEK on inside
MEK welding done, the tiny bit shine you see around the coil wires coming out of the coil base is not MEK, but a little liquid wire insulation, No MEK touches the wires.
Coil ready for epoxy filler.
Next, the end cap unsoldered from the circuit board.
End cap drilled with 1/4"drill and 3/8" drill countersunk hole just started.
1/2" deep 3/8" countersunk hole done.
1/2" deep countersunk hole from the outside, you see there is plenty of room to do this IMO and you are going to fill it back in with epoxy.
Ready for epoxy. You can see some of the black marks on the cable wires so I knew which was which.
One last thing, I forgot to take a pic of the epoxy in the end cap and have already put the circuit board back into the tube and sealed it all up so I could test the coil after the MEK welding was all done on the coil to make sure everything was okay......YEP it works just fine, so pour a little slow cure casting epoxy into the PVC let set, screw on the strain relief and I'm done.
Took a few times adding pieces from an old coil cover and mixing with an old screw driver to get the consistency and thickness I thought I wanted, you will notice I had some fine strings like spider webs of glue on the PVC, I'm going to thin the mix down before doing this again.
Using a syringe with out the needle was the way to apply with accuracy even the "to thick" mix I used went through the syringe okay and I was really surprised, when the syringe cleaned up real nice the MEK had no effect on it and I can reuse it.
I used a pint mason jar to mix in and kept the lid tight, the fumes will eat the rubber seal on the lid so I was careful to wipe the soft rubber off every time I opened the jar as not to get any in the MEK mix and retightened the lid very hard every time(got to get some of them plastic bottles).
I used a piece of 3/4" pvc formed to the shape I wanted with pair of pliers and heat gun.
The cable I used was the Master Carr's unshielded continues flex, 4 connector #9204k12 recommended by OldBeechnut (thanks).
I've now replaced three Excal coil cables with that stuff and love it, just be sure to mark the ends as it has 3 wires in red and one in a yellow/green. I used a black permanent marker to put stripes on the wires after doing a continuity check so I had matching ones on each end, I also drew up a wiring schematic so I knew which ones were going where on the coil.
Since I was going to completely replace the coil wire by hard wiring the cable to the circuit board I had to remove the old cable and unsolder all the wires going through the end cap to the circuit board, again I drew a schematic of all the wires on the circuit board and cross matched them to the new wire.
Note: I just unsoldered the power wires, but still drew them in the schematic to be sure of the replacement positions.
Always ground yourself when handling and working on the circuit board.
End cap preparation: Be careful using the drill as it can grab the rubber and wires, I pulled the copper wires out first with pliers, then after running a 1/4" drill bit through the end cap to remove what was left of the old cable I took a 3/8" drill and countersunk the inside of the end cap's 1/4" hole about 1/2" deep so I could install a small nylon zip tie around the cable then stuff it into the recess. When done it basically looks just like Minelabs. After installing & tinning the wire ends with solder(I use 60/40 electrical solder) I pulled the cable through the end cap. Next, after putting on the zip tie I pushed it all into the 1/2" deep hole and filled with a fast set plastic two part epoxy made for Plexiglas and acrylic applications, I find it works good and does not effect the cable, but you got to be fast as it is quick to set up, it is also used to glue the back glass to convertible car tops and found in Walmart or most any auto parts store. OldBeechnut may have a better epoxy recommendation for this and I hope he will chime in here, but I have used this stuff and am familiar with its properties.
Note: install all O-rings and slide strain relief and end cap's black cover on cables before you solder all the cable wires (don't ask how I know this).:angry:
Here are a few pic of the job and it will be ready to use in a day or two as it is my backup to my backup Excal
Coil repair set up
MEK on outside
MEK on inside
MEK welding done, the tiny bit shine you see around the coil wires coming out of the coil base is not MEK, but a little liquid wire insulation, No MEK touches the wires.
Coil ready for epoxy filler.
Next, the end cap unsoldered from the circuit board.
End cap drilled with 1/4"drill and 3/8" drill countersunk hole just started.
1/2" deep 3/8" countersunk hole done.
1/2" deep countersunk hole from the outside, you see there is plenty of room to do this IMO and you are going to fill it back in with epoxy.
Ready for epoxy. You can see some of the black marks on the cable wires so I knew which was which.
One last thing, I forgot to take a pic of the epoxy in the end cap and have already put the circuit board back into the tube and sealed it all up so I could test the coil after the MEK welding was all done on the coil to make sure everything was okay......YEP it works just fine, so pour a little slow cure casting epoxy into the PVC let set, screw on the strain relief and I'm done.
dewcon4414
Well-known member
Ive got one in that condition setting around..... but ive got a couple of spares now so just not gotten around to looking at the process. Where you getting the MAK and wire? So Mel..... if you didnt have the stuff laying around what would it cost .... wire, MAK, bottle and suringe?
You are wasting time ...... warm weather for Spring Break this year. Im not finding anything but at least its warm this year unlike the past 2 or 3 years. With all the renurishment seems we are just going to be chasing recent drops. Then all the renurished sand wants to move South on us. It'll get going pretty soon im sure.
You are wasting time ...... warm weather for Spring Break this year. Im not finding anything but at least its warm this year unlike the past 2 or 3 years. With all the renurishment seems we are just going to be chasing recent drops. Then all the renurished sand wants to move South on us. It'll get going pretty soon im sure.
Mel Parker
Member
I got the MEK at Ace Hardware (don't use the MEK substitute), the wire came from Mc Master Carr and is about $3.50 per ft which is extremely expensive but the wires are numbered which makes it nice. The syringes less needles you can get in lots of places like West Marine or even your doctor will give you one sometimes. The Nalgene bottles you can get on line or go to the Container Store they have a wide variety to choose from but make sure that the mouth of the bottle is big enough for the syringe to go in. Good luck on all of your repairs!
biglry
Member
I guess I need better glasses as I've never seen the numbers on the wires, I'll look closer next time with a magnifying glass and probably save some time.Mel Parker said:
To the ? about MEK, you can't buy MEK here in CALIF so I order it on Amazon, just type in MEK...yea shipping is about the same as the cost of a qt, but I got the real stuff delivered to my door.
I would have never attempted this repair if it had not been for the great pic and information posted by Mel & OldBeechnut you guys are the best!
OldBeechnut
Well-known member
Haha, funny I never seen the numbers either, now if it was a gold colored ring I would be looking harder I guess....
here is the post for the cable, took me several years to find....I just wish we could find the ones with the correct colors for the battery and the coil cable. I did find a cable that is super flexible for the remote pp
just sent my first two out, Dew you got one and Jeepgold got the other for there PP modes.
http://www.findmall.com/read.php?22,1832298,page=1
NIce work Me Biglry
here is the post for the cable, took me several years to find....I just wish we could find the ones with the correct colors for the battery and the coil cable. I did find a cable that is super flexible for the remote pp
just sent my first two out, Dew you got one and Jeepgold got the other for there PP modes.
http://www.findmall.com/read.php?22,1832298,page=1
NIce work Me Biglry
Mel Parker
Member
They are outlawing MEK in some states because of the pot heads and druggies.
Mel Parker
Member
I'm ready for the water, bring it on. I will be in Florida next month to try it out. When people ask me what the hump is for on top of the coil I tell them it's a power amplifier that doubles my depth on GOLD.
OldBeechnut
Well-known member
mel said:
Thing is you might be telling the truth! Mel the Master Mind behind the Pinpoint mode...
.
Mel Parker
Member
Like you said some time ago, I started the fire and you threw gas on it and it has taken off and you helped a lot of people with the mods and made them very happy. Keep up the good work ole friend!
Mel excellent!!!!
GeorgeinSC
Well-known member
Love the color after painting. Wish the Coil on my Excal was all that color. One should be able to see it much deeper.