A Warning About KBS Clear Diamond Finish

[Mike Griffin]

KBS Diamond Clear is a great one part clear coat and seals bare balsa very well.  I phave been using it for a while now but I need to warn you about something that can get very costly.  I know because I have lost 2 quarts of this stuff by not knowing this and that is over $80.00 worth of material.  

KBS is Urethane based and cures by absorbing moisture out of the air.  I have had two quarts go solid on me because I did not seal up the container tight enough.  You really need an aiitight container to keep this stuff in but here are a couple of things you can do that will keep this from happnening to you.

1.  Pour what you need out of the can quickly.  Take a ziplock bag and open it and push the bottom of the bag down into the can until it touches the liquid.  Then fold the edges of the bag over the can and reseal the lid on the can.  This displaces the air in the can.

2.  Buy a can of BLOXYGEN (Amazon has it)  pour out what you are going to use in a container and then close the lid except for a crack and spray a shot of Bloxygen into the can and reseal the can,  BLOXYGEN is Argon, an inert gas that is heavier than air and it forces the air out of the can and replaces it.  Argon is used in light bulbs and Insulated glass windows

Either way will work.. just dont let yours set up like mine did.  It can get expensive.  Also wipe off the rim of the can and the lid very good or the lid will weld itself to the can.

Kindest regards

Mike

[Steve Thomas]

What's even more annoying is when you've had one lot go hard in the can, so you put the next lot in a glass jar, but the lid of the jar gets jammed on, and then while you're prising the lid off, the jar slips, and half a pint of KBS ends up all over your workbench and floor...

[Mike Griffin]

Steve I did the same thing with a mason jar.  Dont feel bad.  That stuff is not fun to clean up either.  The jar did not even keep the moisture out for me...still turned to jelly....

Mike

[Dan Berry]

Another trick: dump glass marbles into the can which will bring the fluid level up and not affect the product.

[john e. holliday]

To keep lids from sticking on jars with dope or epoxy, use parchment paper.   The same stuff we use to glue stuff together with out glueing to work surface. 

[EddyR]

The answer to saving the unused part is quite simple. I posted it a few weeks ago on this thread.
http://stunthanger.com/smf/index.php/topic,37093.0.html

[Dennis Toth]

I know this is a very old thread but KBS Diamond Clear (https://www.kbs-coatings.com/diamondfinish-clear-aerosol.html) is available in a spray can and it stays for a very long time. I have had a rattle can of this for over a year and it sprays out just like a fresh can. It is very fuel proof after curing for 48 hours.

Best,   DennisT

[Mike Griffin]

I know this is a very old thread but KBS Diamond Clear (https://www.kbs-coatings.com/diamondfinish-clear-aerosol.html) is available in a spray can and it stays for a very long time. I have had a rattle can of this for over a year and it sprays out just like a fresh can. It is very fuel proof after curing for 48 hours.

Best,   DennisT

Hi Dennis,

You are correct and I am pretty sure when I wrote this post, the spray cans were not available.

Mike

[Dennis Toth]

Mike,
You are correct. They came out with the spraycan about 2 years ago. It really makes this a very convenient and easy to use product. I had the same issue the first time I tried it. At the time (~3 ish years ago) I tried the 4oz sample and tried to seal with plastic wrap, didn't work. I have had the spraycan on the shelf for over a year and used it a couple times. I have been working with the Liquitex water based 100% acrylic rattle cans and then top coat with the KBS, works great and just about the same weight as dope. Also been reading about what the scale guys are doing with latex paint. Seems you can thin it out for low pressure spaying and it is also pretty light (what they say is less than epoxy or acrylic enamel (like Rustoleum), overcoat with KBS. Supposedly the important thing is to get latex that is 100% acrylic resin (the most expensive). The big advantage is it can be tinted any color you bring a chip for. I did a quick compatibility test with just some cheap latex I had in the house to overcoat with the KBS spray, worked just fine. Might try it on something small. Would be great to be able to get different colors that aren't $75 a pint.

Best,   DennisT

[kevin king]

Another good tip for latex is always use a mat or eggshell latex, because gloss or semi gloss can cause problems with some clear coats being applied on top. Thats the way to get around it.

[kevin king]

Ive heard alot of positive things about this KBS paint, flexible, fuel proof, can be cut and polished to a mirror finish...but are there any downsides to it, aside from the lid getting stuck?

[944_Jim]

Mr. Dennis,

What do you prep the airframe with prior to painting latex? I suspect this is a grand place for nitrate...especially for small builders using DocSpan.
How long to you wait for latex to cure before topcoating?

Thanks in advance.

[Dan McEntee]

Ive heard alot of positive things about this KBS paint, flexible, fuel proof, can be cut and polished to a mirror finish...but are there any downsides to it, aside from the lid getting stuck?

   Do a really good search on the forums here, as I seem to recall as many problems with the KBS as anything else. Time goes by, it doesn't get mentioned any longer because people stopped using it, then it comes back around again like most things and the cycle starts over with newcomers.

  Type at you later,
   Dan McEntee

[Dennis Toth]

I use regular sig clear dope (I have a lot that was given to me years ago, nitra should also work) to prep frame with silkspan over wood, fill with ~4 - 6 coats then ready for primer (Harbor Freight stuff). I let it cure out about three to five days.

KBS only downside we have found is using it from cans rather than the spraycan. One of the big reasons they stopped using it was the stuff going off in a partially used can. Doesn't happen with the rattle can version now available.

In a regular can it is very hard to seal it off from air and it cures from contact with humidity. Mike G had a way of using a ziplock bag to fill the space and seal which will by some time. Another way is to use a seal gas injected to the can just as you cover. It supposed to push out the air and does not have any moisture so the KBS clear doesn't react. Before applying over any color (dope, waterbase acrylic, laytex) let the finish dry/cure for at least 4 ish days.

Also still need to use a paint mask (not an Airpack) when spraying. It is not as toxic as 2K stuff but KBS recommends using a mask.

The real answer is the to purchase it in the rattle can. Spray on in thin coats, this is important.I have had a rattle can of it for over a year and used small amounts from time to time and it flows smoothly. Just shake rattle and go!

Best,   DennisT

[john e. holliday]

I guess that is why a jar of polyurethane turned into jelly with the thinner on top.  Almost a quart thrown in the trash.  Oh the parchment paper didn't let anything leak ut though.

[Steve Helmick]

Dennis Toth's mention of Hobo Freight primer brought something to mind...not at Hobo Freight, but Tractor Supply, actually. TS sells a lot of stuff that you'd swear came to them from HF. So, I picked up a can of paint at TS, read the label and put it back down, thoroughly confused. On the label, it was called enamel in one place and lacquer in another. 

Made in PRC, it made me want to run screaming from the store. I just walked quickly to the checkstand with the GreenWorks corded electric chain saw...also made in PRC...but every homeowner with trees on their property should have one. Their HQ in Norte Americano is in Canada, but they did me good on a warranty problem. Motor wouldn't keep the smoke inside.  Steve 

[goozgog]

I've been using Moisture Cure Polyurethane
for over twenty years and never had it go bad
on the shelf.
  What I do is puncture the lid with two sheet
metal screws.  One at 6 o'clock and one at 12 o'clock.

  I decant what I want into a disposable cup.
A little goes farther than seems normal.
   If I only need a little I remove one screw and
squeeze the can a little. If I need a lot.I remove
both screws and pour,
then IMMEDIATELY replace the screws in the lid.

  FWIW, this stuff is toxic. I take it outside and wear
a ventilator.  I know everyone here knows that but
it doesn't hurt to say.

Cheers! - K.

[Dennis Toth]

Ken,
What brand of Moisture Cure Polyurethane - website? I assume you use it as a topcoat? Is it crystal clear? Is it nitro fuel proof or gasoline?

The KBS in rattle can (https://www.kbs-coatings.com/diamondfinish-clear-aerosol.html) is crystal clear, very convenient and eliminates the problem of shelf life. So far it goes over everything. I get mine locally at Glue Products (~$23 for 16oz), they are a resin, fiberglass seller with other stuff we use. KBS also sells a "Paint Saver" that you can inject in the can (would work really well with your two screw idea) to push out any air if you want to use a can version.

Best,     DennisT