Having done epoxy laminations since 1965, I can say, yes it helps very much, I hated sanding epoxy before a surfacing agent was developed, resin “worms” would roll out from under the sanding pad, I got #80 wet and dry and did the run with water, it didn’t make much of an improvement. None of my sanders got hot to jump on epoxies, they were a plain pain in the ass to run through a polyester factory. I had gotten back into building EPS and epoxy boards before Clark pulled the plug, Greg came to me with his additive F and I was off to the races, makes a world of difference
Thanks Jim.
I’ve experienced those sanding “worms” you speak of… Much, much less of an issue the longer you let the epoxy cure…
Not the answer a production shop is looking for though… I’m sure…
If I were to hazard a guess as to what’s really going on : I’d say the xylene draws (or evaporates) out the “fatty” components from the epoxy ,leaving a more brittle, easier to sand surface… Just like it draws the fat tissue out of your bare hands…
The additional wax or whatever it is , hanging in suspension , makes the whole job easier yet…Jmho…
VanHelsing…
Jim Phillips or Van Helsing -
Do either of you use additive F in your laminations or is it just a fill coat thing?
I did my best to fill a cap full of AddF and measure the volume....came out just under 7.5 ml. Thats maxed out with stuff spilling everywhere.....
So The Low Tech Lab would say that a " Cap Full" of AddF is about 6 ml.....Got it?
Instructions on the can say "One ml per each ounce hardner".
10 ounces of resin + 5 ounces of hardener = 15....good for a lam on a shortboard or fish....that would be 5 ml of F if you read the can.....but 1/2 cap full would be best if you listen to JimP or Stingray...that would be just under 3 ml....aka about 2.5cc.......
are you confused yet?
Get a Syringe from your local nurse or first responder. Use a sharp object to scribe lines in the plastic at each ml / cc....................learn the metric system... or add 1/2 cap full of F......
Fun Stuff................Stingray
Hi John
The only goal of Additif F is to avoid blush. Blush destroy adhesion of new coat, big problem for the way PE like most glasser work. So Additif F is a lam agent but as blush keep surface “soft and clog sand” no blush epoxy have higher barcol hardness and sand better. Xylene is just the solvent that allow solid contains to spread over the surface protecting it to air humidity. But insert solvant in epoxy resin modify mechanical properties. For example, glycol is a plastifier agent, methanol is a “porous” agent etc.
I use many time addF with RR resin both in lam and sandcoat never have a problem.
I don’t use it anymore since i use my hotbox. Hotbox is a far better way to increase barcol hardness, and better it increase toughness too. On last i use peelply on last layer lam, no more blush, flatter tighter lam and near no sand before finish coat. In fact i just finally use some technics i see in high tech composits buiding parts company i work with 5 years ago. Salt water and eps foam soften brain LOL.
Sorry for my franglish
whats your schedule with the hot box ? why does it stop the blush ?
is the box hot when you put the board in? or do you warm it up after the board goes in ?
what sort of temps ? for what sort of time?
i like the idea of not using F so i can just get on with the job, plus one less chemical is never a bad thing !
Xylene:paraffin Solution
The xylene dissolves the secret 15% component in Additive F, or the paraffin under discussion – xylene creates the carrier solution. This would produce an even dispersal throughout the mixed epoxy.
In theory, as the epoxy polymerizes, forming cross links, the paraffin could be excluded from the the molecular lattice. This might push the paraffin to the surface as a very thin layer – xylene would volatilize. The remaining thin surface layer of paraffin might protect the epoxy surface from humidity during curing. However, I question whether bonding with the next coat of resin would not be compromized by paraffin.
Additive F
According to Greg Loehr:
In laminating, (Additive F) it helps wet the cloth eliminates most air bubbles, especially around wings and boxes, reduces the amount of resin needed, and most of all eliminates blush. Blush is what causes the banana peel effect you were referring to. In hot coats it eliminates blush, fish eyes, other surface blemishes and increases Barcol hardness. This increase in Barcol makes the board sand easy and improves the bond and strength between layers.
Amine Blush
Web definitions:
|
This was written well enough. I see no point in writing a summary:
http://www.yachtpaint.com/usa/diy/ask-the-experts/what-is-amine-blush.aspx
What is amine blush?
When using a solvent free epoxy resin... **After application and during the curing (drying) process, the epoxy releases a blush to the surface called ‘Amine Blush’.** This blush is known to appear as a ‘wax-like’ film that sits on the surface of the cured epoxy resin. This amine blush will in fact keep some subsequent products applied from fully curing, performing correctly and also yellowing unless removed properly. The visibility of the blush will be determined by the moisture in the air during the curing process, however will still be on the surface if not always visible. **The best way to reduce blushing is to work in warm temperatures (the epoxy sets up fast, reducing the blush window) and with humidity at low levels. It would be best to avoid conditions where moisture is coming out of the air as temperatures fall.**
How to remove it?
Interlux recommends thoroughly washing the cured epoxy with clean warm water, all-purpose soap, and a stiff brush or Scotch-Brite™ pad. The amine blush is water soluble therefore the only way to completely remove this is by following the instructions above. You will want to clean the amine blush off of the epoxy before sanding as well. **If you begin to sand before removing the amine blush, you may sand the blush deeper into the surface making it much harder to remove. **It is a safe practice to clean all types of epoxy resin, even if the label states that it is ‘amine blush free’ or ‘no blush formula’. Please note: **Aggressive solvents like Acetone will not remove the blush.**
What will it do to my project?
**If amine blush is present on the surface and is not properly removed, you might not notice a problem with your project until after it is completed.** If you use a single-part primer such as Interlux Pre-Kote and do not remove the amine blush, the blush will migrate through the Pre-Kote to the top of the surface causing the Brightside® single-part polyurethane finish to improperly cure from the contaminated areas. It could also lead to detachment of both primer and finish. ... **Some epoxy resins can take up to 2 weeks to fully cure, still releasing amine blush to the surface. **
****_____
http://www.westsystem.com/ss/assets/Uploads/Ew20Contamination.pdf
However, most adhesion problems can be traced to some form of surface contamination.
Amine blush may be formed when epoxy cures. Amine blush is water soluble. Many organic solvents are completely ineffective for removing it. That is why we suggest washing an epoxy surface with water (water clean enough to drink) using a Scotch Brite™ pad (or wet sanding with waterproof wet/dry sandpaper) and drying it with paper towels before continuing with another operation. Soapy water, or water with ammonia or bleach, is not necessary and may leave a residue—another possible surface contamination.
_____http://www.polymer-services.com/AMINE%20BLUSH%20v2.pdf
Amine-cured epoxy formulations are widely used in ambient temperature cured coatings and flooring applications. Theses products are also used more and more in cold temperature applications. (See Successful Cold Temperature Application on the Technology Update page). **If amine-cured epoxy resins polymerize during conditions of cool ambient temperatures or high humidity, i.e. condensation on the coating, they may develop an amine blush. **The amine at the coating surface develops as an oily, waxy or milky film, sometimes amber to clear in color.
The amine component reacts with moisture and atmospheric carbon dioxide to form ammonium bicarbonate and/or ammonium carbamate. This may or may not be visible on the coating’s
**surface but can interfere with adhesion if overcoated. **Contractors and inspectors should be alert to this phenomena and test suspect surfaces.
These amine compounds are often hygroscopic and very efficient scavengers of carbon dioxide from the air, even though carbon dioxide is generally present at about 360ppm in outdoor environments. In indoor environments with human activity this may be increased 2-3 times. In the presence of gas burning motors (fork lifts, tow motors) and salamanders etc., the carbon dioxide would be even greater. These sources of heat may also produce copious quantities of water vapor resulting is exacerbated blushing problems.
If amine blush is detected it should be removed.
hygroscopic – **absorbing moisture, **capable of easily absorbing moisture, e.g. from the air
Carbon dioxied is highly soluble in water (i.e. moisture).
Hello John.
I vacuum bag on the laminate so there’s no need… Only in the sanding coat… And like Stinray and Jim mention, only half as much F as suggested…
VanHelsing.
“Science” is your friend …
Additive F eliminates blush chemically instead of all the other companies who expect you to do all that extra work removing it physically. It was originally designed to make sanding easier but it turned out to have many other functions. It’s been around for about 15 years now and has never been changed because it is so effective at what it does. It doesn’t effect the strength of the cured product at all, in fact it only increases barcol hardness. IMHO if you want to work twice as hard to get half the result, skip Add F. But for most boardbuilders it’s an incredible invention. And yes, if your vacuum bagging you don’t use it.
1 Like
just curious… what does the “F” stand for, anyway??? (Was there an Additive “E” before this one?)
[quote="$1"]
[quote="$1"]
[quote="$1"]
[quote="$1"]
Greg Loehr has stated repeatedly here that it is NOT wax mixed with Xylene. I believe him.
[/quote]
But if it was as simple as that, would you expect him to give out the recipe?
[/quote]
I dunno, maybe not.
But, I'm pretty sure he's not making his millions off of F.
Besides, he's never lied to me before AND, he's proven to be pretty forthcoming with a lot of info that he doesn't HAVE to share.
Seems to me to be one of the good guys.
[/quote]
Hi Chris,
I was going for more of the comedy than a true analysis of Additive F.
It probably isn't wax in Xylene, but another solid instead. Something that doesn't harm the bond to the next layer of epoxy.
[/quote]
That makes sense Mark...
I haven't used the stuff in a while...
Might start using it again.
F stands for Flow, flow additive was the original intent. Does a lot more than that though.
Hey, that rhymes.
thanks Greg. I am about to hotcoat/fillcoat an EPS board I glassed with RR, its coming out good so far…didn’t use it in the layup but I’ll go with the flow and try some F in the next step. Oh, and Happy New Year!!
Why not just use additive F?
It’s cheap and it’s Tried and True!
There are more important battles in life!
Kind regards,
surfding
I have used Additive F. It worked work well. Will probably use it again. But,
I’ll just have to remember there may be a limited shelf-life.
I use it in laminations and hotcoats, per manufacturer’s recommendations. I get top notch results with minimal prep and reasonable production times. I don’t want to risk using any home remidies, knowing the real special sauce is out there.
As for the stuff going solid on you… buy small amounts, and use it up. I figure I use about a half oz per board. I order 2oz bottles from www.GreenlightSurfSupply.com and I get 3 to 4 boards out of a bottle. Keep it fresh…
heat it up and it will come back to life ( by heating in hot water ) no open flames
Last Add F I got came ina a little jar from Fiberglass FL or greenlight (forget which).
Xylene or other, the solvent evaporated out before I could use half of it.
So, experts, would adding back a few cc of xylen AND heating it revive it better than just trying to reheat the glob of glop?
BTW I will just buy more, but asking for “next time” …