Alternative UV cured Resins?

[Brightraven]

Hi there,

Recently I’ve read up on certain alternative resins that can be used in any temperature, that are subsequently cured by the UV of sunlight, without the need to be mixed with any MEKP hardeners. One of the more commonly used ones is Solarez, but there are also some nontoxic eco-friendly resins like PhixDoctor that have no VOCs and apparently work very well for sealing dings and cracks in certain resin and epoxy coated watercraft. I have read that these products are really popular for surfboards and SUPs but I have not heard of them being used to repair cracks and chipped areas of canoes (though a kayaker once told me he uses it very successfully for his hull). I did talk with someone at PhixDoctor over the phone and he said their product would work great for the few cracks and small gouges in the vinylester resin of my Northstar Trillium.
I am curious to know if anyone here has used these kinds of products and how it went. I’d like to still go out on the water in these chilly autumn temperatures but want to make a few repairs first and don’t want to wait until the temps reach 70 degrees before I can do that with the traditional hardeners and resins...
Plus if I can do without a respirator and it’s better for the environment that would be wonderful.
Thanks and wishing you all well!

 

[Alan Gage]

Epoxy doesn't need to be mixed with any MEKP hardeners either and for small repairs a respirator is generally not deemed necessary (even for large projects many people don't use them). It hardly smells at all. Many of the faster setting epoxy/hardener combinations can be successfully used at lower temps (maybe down to 55?) and there's also the option of draping plastic over the hull and placing an electric heater underneath to raise the hull temp in an otherwise unheated area.

The UV cure epoxy/polyester resins look interesting. I just looked quick but I didn't see any mention that they do/don't cure in low temps. Are you sure UV is all that's required even if the temps are low?

Personally I'd stick with epoxy for what you're looking to do but that's mainly because I know it works, I'm familiar with it, and I'm pretty much done with experimenting and trying new things. And from what you describe I'd probably go ahead and keep paddling this fall and fix it up over the winter in a heated space.

Alan

 

[goonstroke]

While you may not be able to epoxy in the dead of winter, I wouldn't think you'd have to wait for 70. For the most part a lower temp will just mean a slower cure. An overnight cure outdoors might be foolish because of dew, squirrels, etc., but I'd think you could do some significant work on a warm dry fall afternoon (50?). I had a phone conversation with someone at Raka before doing some spring repairs on a boat I was impatient to use, and my recollection is that the thumb rule is cure time doubles for 20 degrees F. (Can anyone confirm? I don't have that written down anywhere, I might be confusing it with the rule for decanting cheap wine.)

I'm also curious about the UV stuff for composite canoes. Maybe someone can do an experimental skidplate.

 

[Brightraven]

I am not clear about the compatibility of epoxy and vinyl ester resin...I would assume it would be fine to use epoxy, though it seems there are people who are adamant that the same resin be used.

I am definitely intrigued with these alternatives, especially "PhixDoctor" which is no VOC and nontoxic to the environment. I spoke with the guy who runs the company and he stated the UV cured products can work in any temperature, even freezing, and that the Dura Resin he sells is compatible with vinyl ester resin. It should be applied in the shade, and then needs only sunlight to harden within a couple minutes.

And then, according to the Solarez site (a competitor with similar products without the super low toxicity of PhixDoctor, but still less than traditional epoxy/resins/hardeners):
DOES HEAT OR COLD AFFECT THE SOLAREZ® REACTION?
No. And this is a tremendous advantage over conventional M.E.K.P. catalyzed resins which barely even work at temperatures below 60°F and are dangerous over 85°F. On the other hand, SOLAREZ® works just as fast in scorching heat or freezing cold.
IF SOLAREZ® ONLY TAKES 45 SECONDS TO GEL, WILL I HAVE TO RUSH MY REPAIR JOB?
SOLAREZ® quickly hardens but only when exposed to direct sunlight. In the shade, you have all the time you need to put the goop where you want it and to remove excess bubbles.
When I contacted Solarez about the vinyl ester resin of my Northstar, they recommended a vinyl ester resin product they have that does not need hardener, but only sunlight...works in any temperature and cures extremely fast.

I'm intrigued so I purchased some from each company. I'll try one or both of them and report back...

 

[Brightraven]

Humbled with this process and embarrassed to show you all my crappy work, I am looking for some assistance and words of wisdom here, to hopefully remedy this eyesore of what was supposed to be a very simple project I found myself enmeshed in…

A few days ago, I was experimenting with some UV Resin I wanted to use to fill in the few minor surface level chips/gouges in the Vinyl Ester resin of my carbon/kevlar Northstar Trillium. I had contacted the maker of the product (Phix Doctor) and he said it would be a good match for what I was looking to do, and was easy enough. I wanted to use this product because it is nontoxic, no-VOC, instantly hardens in sunlight, and can be used in any temperature.

So, I taped off the area in need of attention before applying some light sanding over the gouges with 150 grit. Then I applied the UV resin in an area of my garage away from any sunlight; however I didn’t realize I had used way too much of it before placing a clear plastic sheet over it to smooth it out, but it still had a relative thickness that was a bit higher than the hull itself. When I took the boat out into the sunlight, I let it soak in the rays for a few minutes before taking the plastic sheet away. Voila! It was hardened and did the essential job of filling in the cracks and gouges, and I was super impressed with the efficiency and non-toxicity of this product. However, because I applied too much, I had to sand it down… I went from 200 to 400, etc, up through various grits, wet sanding by hand all the way to 2000…and in the end, I just made a big mess of it all!

Since I sanded, the hull feels nice and smooth now but I actually went a bit too far down I think, because the color is slightly off...and now there is this big rectangle of faded hardened sanded resin that I don’t know what to do with. There are also visible scratches on the edges of this rectangle that I made with the sandpaper. Is there any way I can make this look normal again, so that this area seamlessly intermingles with the rest of the hull and no one would ever notice?

I’ve never done any of this before and am learning what I can through YouTube videos, but it gets rather tedious to sift through video after video and not find what I’m actually looking for…Do I just buff/polish with some kind of compound? Should I reapply the same UV resin and bring it down again in a different way? Should I wait until springtime when it’s warmer and use the original Northstar vinyl ester resin with hardener and then bring that down? Am I missing some essential step?

Would appreciate any help. Thanks so much!

 

[Mike McCrea]

If that area has not yet been epoxied (estered or etc) it may vanish entirely when topcoated. With some kind of clear resin it will at least be far less noticeable.

Quick test – if you wet it down with a sponge is the area less distinct?

 

[Brightraven]

If that area has not yet been epoxied (estered or etc) it may vanish entirely when topcoated. With some kind of clear resin it will at least be far less noticeable.

Quick test – if you wet it down with a sponge is the area less distinct?

When I wet it with a sponge, one would never know that spot is there...
As the water dries, that spot becomes more and more apparent.
My only concern was if I placed a thin layer of ester or epoxy there, then would it create an extra shiny rectangle to stand out rather than an extra dull one...?
I’d really love for it all to disappear and have a seamless integration with the rest of the hull if that is possible.
Many thanks

 

[Traveler]

That would be my advise too - wet down the area with a little water or rubbing alcohol and I bet that almost all of the discolouration will disappear. Once that is confirmed, dry it and apply a couple of very light coats of a clear varnish to the spot and it should be back to where only you will notice it.

 

[DuctTape]

I originally read the title as ... cured RAISINS.

lolol

Carry on.

 

[scoutergriz]

When I wet it with a sponge, one would never know that spot is there...
As the water dries, that spot becomes more and more apparent.
My only concern was if I placed a thin layer of ester or epoxy there, then would it create an extra shiny rectangle to stand out rather than an extra dull one...?
I’d really love for it all to disappear and have a seamless integration with the rest of the hull if that is possible.
Many thanks

you can always cut the gloss with a #1000 sanding pad or an abrasive scrubber, or use a low or semi-gloss finish.

 

[Brightraven]

Thanks for these tips...I'll experiment with applying a thin coating this weekend...