The beaten dead horse rides again !!! LOL,
The Qs have been answered HERE, more than once,and at least 100Xs in the arcjives
But once again…
40 grit works fine for this app.
Acetone wipe also works fine or even styrene…
NOT MEKP…YOU’LL just cook the plug and hole.
H
I have been watching this thread with fascination. I originally thought it was a typo…MIBK, MEK, MEKP you know 220, 221 whatever it takes. But then Ron from FCS confirms no typo, but really MEKP.
So, a slightly educated guess as to why it works. MEKP is an organic peroxide which as a class of chemicals are potent oxidizers. Bonding to plastics is difficult because of their low surface energies. Low surface energy means the adhesive can’t wet the surface very well and wetting the surface is key to adhesion. I am guessing the new plugs are some sort of glass filled nylon or delrin and hence have relatively low surface energy. The MEKP may slightly oxidize the plug surface which raises the surface energy and voila better adhesion… The same thing is done with corona discharge when people want to bond or print on low surface energy plastics like polyethylene. corona discharge
So, alternatives are have a corona discharge device handy, a quick pass of the plug through an oxidizing flame (not in the same room as your resin etc please) or maybe you have a stash of another oxidant like ozone handy. There’s a world of excitingly dangerous methods to make a stronger board! Or you could just lower the surface tension of your resin…oh wait somebody has already done that.
Rob
ok the answer may be
ron should personally dip all plugs prior to dispatch
to those of you that think it is ok do you want to volunteer to do 10 instals a day
everyday hmm
darker than dark
Thanks Rob.
Sad git that I am, that is exactly the sort of answer that I was looking for. When bonding some plastics with epoxy I often use the flame trick to activate the surface. This is just an extension of that. Both have safety issues!
See chaps, now I have an answer I’ll return to obscure silence on this issue, bye,bye!
Cheers
Rik
MEKP is an organic peroxide
Nuclear waste is organic…maybe FCS should dip there plugs in that.
The idea of sanding,wiping or dipping(dippy for some) is to remove the shine which translates into mold release on the surface of the box/plug,that is left behind after it is pulled from the mold…that’s it.
The plastics are,or should be co-polymers and will bond w/o extensive measures like grooving the sides,etc.Once the box is installed and cured it’s no longer a box,resin filler,foam and fiberglass…it’s one body…fused…that is if the installer did his job correctly.
In most cases of material failure…it’s the installer’s fault(w/ FCS PLUGS BEING THE EXCEPTION of course).
MEKP IS OVER KILL.
But what the heck ,let’s use 4 gallons of resin per board,that way we won’t miss a spot !
H
Hey Herb,
I’m not sure why you chose to quote that phrase, but I think you may be misinterpreting why I used the term “organic” here. When dealing with chemicals, organic means it contains carbon (as in volatile organic compound), not that it is some sort of free-range molecule raised without pesticides. Technical jargon (especially concerning chemicals and their associated abbreviations) is often used rather loosely on Sways, but in this case I was using organic from a chemist’s definition.
I wasn’t advocating the MEKP treatment, just suggesting why it might work which might include oxidizing some residual mold release as well as what I said earlier.
Rob
Hey Rob,
I meant no harm.
I see a possible mis-use here w/ MEKP as a dip by some ,less experienced installers.
The information you give is absolutely correct(OUTSTANDING), if the job’s done right.
And,actually,Sandpaper is the safest,and most commonly used tool for this app.
As far as my post…chalk it up to a rather…rare day.
Have a great evening,and a better tomorrow.
H