Poly Resin question

[Axkiker]

I have been wondering something about the different type / brands of poly resins. When I started my project I knew nothing about working with resins. Now that I am 75% complete I know just a little more than nothing but im getting there. My understanding was that for a poly resin to dry tack free a wax must be added unless the resin already has the wax added. I have been purchasing my resin from fiberglasssupplydepot.com and must say am very impressed with the product. The descrption states you do not need to apply wax for a tack free sandable surface. So I just went to town and it does dry tack free. I noticed the other day that the container of resin states you may add wax at a specific ratio. Why would this be needed if its got the wax already in it.

Soooo this got me wondering if this stuff already had wax in it, or if it was able to harden some other way.


below is the description from the website

Our polyester resin is a Iso blend resin, this is a perfect no-run, no-sag resin for marine repairs and boat construction. Iso resin is more flexible and waterproof then your traditional 100% polyester resin. Ideal for repairing hulls, decks, cabins, and tanks. Good for repairing all boat surfaces. It is mixed with MEKP catalyst to harden. This resin is a low profile resin that does not need wax for it to dry tack free. This is the resin that most of the boat builders use when building new boats. Recommended you add hardener at 1% or 10cc per quart. This gives you approximately 20 minutes of working time.

Any thoughts??? The description doesnt say anything about having wax already in it.

 

[Mikeopsycho]

I can't really answer your question, but I can add a bit more confusion. The two first 5 gal buckets of resin I bought had a kind of bluish colour to them, and remained very tacky after curing. The third bucket I bought in the heat of the summer was a brownish colour, and dried pretty much tack free. I phoned the supplier and was told they mix batches a bit differently depending on the season, and this particular batch had no (or less, I can't recall) cobalt, and was the correct stuff given the hot weather. My fourth can was back to blue, and was very tacky after curing.

All buckets came from the same manufacturer, all were marked identically, and the 'unwaxed' check box on all the labels were checked, the 'waxed' box was empty on all cans.

So, maybe having less, or no cobalt in the mix causes more of a tack free cure..:noidea:...just a guess.

 

[Rickmerrill]

I'd just call them and ask, then report back cause I'd like to know how a wax free dries tack free that quick.

 

[mercurymang]

It's also important to define tack free, If you mix up a batch of poly resin and let it cure, that outer layer may appear to be tack free but if you push it with your finger, you will probably see fingerprints left on the surface upon closer inspection.
If you mix up a batch with wax and let it cure, and then wipe it off, there will be a difference. You will not be able to leave any finger print on the surface. It will also be much slicker and will not become cloudy if exposed to water.

 

[Woodonglass]

MM is absolutely correct^^ It's about the Degree of Tackiness. There are 3 basic kinds of Poly resin. Ortho, Iso, and Vinyl in that order of quality. There are about 5 major MFG of the stuff in North America. They are all about the same in their chemical Make ups. All different color combinations. Some Will cure differently than others and there are a myriad of variables that determine cause all kinds of quirky things to happen during the curing process. Bottom line is there's just no way to give a definitive answer to why or how one will react one way one time and then another way another time. It's kinda like teenagers...If anybody ever figures them out...Please LET ME KNOW!!!!:facepalm:

 

[Axkiker]

Im gonna do some checking and maybe call the mfg and check. The container doesnt say that it doesnt contain wax, it just says you can add it if desired. The description says wax is not needed to dry. Kinda confusing....

I can tell you this, if the stuff is remaining tacky it isnt enough for me to tell. I have plenty of containers where ive mixed and had leftovers which harden. You definitely cannot leave fingerprints in it as it seems hard as a brick. It also sands very well and doesnt clog the paper as is typical when sanding paint or primer that isnt completly cured.


Ill have to do some more checking.

 

[undone]

In the description it says it's an ISO blend, that's the key, it's an iso DCPD blend. The DCPD portion will cure tack free rather quickly, and is normally about 80% of the blend, 20% being ISO. You are not dealing with the manufacturer, only a repackager and reseller of the resin.

 

[Rickmerrill]

Think you're on to something there undone. I was checking on DCPD and found this from ondarvr.
http://forums.iboats.com/forum/boat...4678-dcpd-blend-and-ve-iso-ortho-blend-resins

 

[Woodonglass]

I remember that now!!! I sure hope Ondarvr is OK. He hasn't posted on the forum in quite some time. I've learned sooooo much about Resin from that guy!! He is TRULY and expert on the subject!!

 

[Axkiker]

In the description it says it's an ISO blend, that's the key, it's an iso DCPD blend. The DCPD portion will cure tack free rather quickly, and is normally about 80% of the blend, 20% being ISO. You are not dealing with the manufacturer, only a repackager and reseller of the resin.

Yeah I was hoping they may tell me who it was but it appears you all may have it figured out.

 

[Axkiker]

So I think I'm still confused after reading the linked thread. Is a wax agent used in this blend at all?.. If it's a partial blend it seems it would have some. Are there advantages or disadvantages to this blend. So far just from working with it the stuff seems great Just would like to learn more if possible

 

[undone]

It has no wax, it's the chemistry of the DCPD resin, it's not as air inhibited as an ISO resin so it becomes tack free quicker and easier. You could add wax to it if you wanted, and in some situations It may help, but normally you wouldn't. The tack free surface also means you should sand it before applying another layer.

 

[btravlin2]

More expensive, but I use epoxy so I have a quick tack-free surface, and of course, the adhesion is much better on wood. It's just better for assembling things.

 

[Woodonglass]

I spent a lot of time researching all this a few years back...but now...I realize all the resins are pretty much the same. I just pour em, spread em and move on. I let the MFG's worry about all the Molecular/Chemical Reaction stuff. If it works...It works and that's all that matters to me!!!!

 

[mercurymang]

Man, talk about confusing information. Why would they say on their product that "You may add wax at a specific ratio"?

 

[Woodonglass]

What's confusing?? You MAY add wax to any/all laminating resin if you want, to the last layer to get a totally tack free surface. It's not absolutely necessary. Poly resin will eventually cure tack free it just takes some longer than others. All the wax, or PVA or Plastic or any other method does, is block the air from the surface. This is what makes it cure faster. When air cannot get to the surface it will cure quickly. The ratio is usually around 1/2oz of wax per qt of resin

 

[Axkiker]

What's confusing?? You MAY add wax to any/all laminating resin if you want, to the last layer to get a totally tack free surface. It's not absolutely necessary. Poly resin will eventually cure tack free it just takes some longer than others. All the wax, or PVA or Plastic or any other method does, is block the air from the surface. This is what makes it cure faster. When air cannot get to the surface it will cure quickly. The ratio is usually around 1/2oz of wax per qt of resin

Well, because in the description it states that it drys "Tack free" without needing wax. I can attest that this is indeed the case as after a day of setting it is absolutely 100% tack free.

Soooo why would wax be needed..ever... What would be the advantage in any situation. As stated in a previous response its the chemistry of this particular mix that makes wax not needed.. If its not needed it just seems its not needed.

So I just dont see why the packaging says wax can be used. Doesnt seem there would be a benefit.

 

[undone]

There are different levels of tack free, and different time frames. You have used one resin in a limited way and found the surface to be relatively tack free, but you don't really have anything to compare it to having never used a different type of resin or this one with wax. With wax added the surface will have a slightly different feel and be tack free rather quickly. Plus people frequently put a coat of resin over the final layer of glass once the laminate has hardened, this thin layer of resin won't cure as well due to it being so thin, the wax helps the surface to be tack free when it may not do it well on it's own.



PS. Wax also helps prevent the surface from water spotting. If water comes in contact with the cured surface too soon it can leave a milky whitish surface defect, without wax this could still happen a week or two after the resin becomes hard, sometimes even longer. With wax added this timeframe is reduced to a couple of hours.

 

[Rickmerrill]

Axkiker, the labeling probably has something to do with something like a customer who needed a fast complete cure (not just tack free) on a production line before they could move onto the next step or maybe just some marketing genius that was afraid of loosing a sale because someone would think this resin is somehow "different" if they said it didn't need wax. Yah never know...

Interesting this came up when it did. I just opened the first pail of my second batch of resin and it is "different" just like Mikeo said above. It tacks up much quicker and it's not gummy to sand. The one downside is that it seems less viscus - when I do a vertical lamination it continues to slowly run to the bottom the entire time. I guess that's proof that I'm using too much resin during wet out. It also doesn't hold vertical pieces in place while you're positioning the cloth nearly as well as the old batch did. I guess it's their winter blend.

 

[mercurymang]

Along similar lines (and i was thinking of performing this test myself) is strength. Is a faster cure stronger that a slower one. It seems that some of the batches I made that kicked quickly were stronger than those that I mixed with less resin and tool longer to cure. Nothing scientific, just seemed that way.