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XCR resin sanding problems
XCR resin sanding problems
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XCR resin sanding problems
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ZABAS
Z
ZABAS
posted 6 Years Ago
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Z
Group: Forum Members
Posts: 16,
Visits: 30
I'm using XCR coating resin since last year. And never had difficulties to sand it dry. If it was hardened for at least two days, dry sanding always went smooth. But I've experienced the opposite this Summer. When it was impossible to dry sand resin that was hardened for 4-5 days. It clogs sandpaper or Abranet immediately. Also noticed weaker adhesion properties of that resin, no matter that previous coat was sanded with 220 paper. I have suspicion that it has a lot to do with air humidity. But maybe there are some additives available that would help to avoid such problems ?
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ZABAS
Z
ZABAS
posted 6 Years Ago
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Z
Group: Forum Members
Posts: 16,
Visits: 30
I've ordered 1kg XCR yesterday. Will see how it behave. I have suspicion that only this particular batch could have problems. If that will prove, I would like to return one unopened 5ltr package.
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XCR resin sanding problems
ZABAS
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6 Years Ago
The formulation of the resin has not changed so I would not expect the behaviour of the resin to fundamentally change. It could be environmental as you suspect, although you would expect it to settle...
Warren (Staff)
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6 Years Ago
Thanks for immediate response :). How would you recommend what point of humidity is advised not to pass to expect good hardening process ?
ZABAS
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6 Years Ago
There is no easy answer unfortunately as it varies resin to resin, also with temperature. Generally you may get away with a higher level of humidity at higher temperatures as the temperature can help...
Warren (Staff)
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6 Years Ago
I'm asking particularly about XCR resin. Anyway gonna hang higrometer in workshop. Probably I will report you more precise numbers :).
ZABAS
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6 Years Ago
Unfortunately there are too many factors and variables at play which can have an effect on how sensitive to moisture the resin ends up being in a set situation. Hence no precise manufacturer data...
Warren (Staff)
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6 Years Ago
Hi Warren. I'm worried about XCR resin behavior. I have put one layer of hotcoat on EL2 resin. It feels a little sticky even after 4 days of curing. This time temperature and moisture in workshop was...
ZABAS
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6 Years Ago
I've ordered 1kg XCR yesterday. Will see how it behave. I have suspicion that only this particular batch could have problems. If that will prove, I would like to return one unopened 5ltr package.
ZABAS
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6 Years Ago
Strange that you have more issues. that batch last sold about 3 months ago so is less than 5 months old overall. We haven't had any reports of issues yet so it is useful to work out what is going on.
Warren (Staff)
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6 Years Ago
The resin underneath is hard. It looks like it is covered by thin softer ( waxy ) layer.
ZABAS
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6 Years Ago
waxy surface? did that come off easily? Sounds like a bit of amine blush which could be caused by a couple of factors.
Warren (Staff)
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6 Years Ago
That does not come easily, only with sandpaper. But only wet sanding possible. Or using kilometers of sandpaper. It looks like good glossy surface. But when touching it with fingers and holding finge...
ZABAS
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6 Years Ago
A light tack would suggest that the resin hasn't fully cured properly for some reason, be it a mixing or measuring issue or some kind of contaminant inhibiiing the cure.
Warren (Staff)
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6 Years Ago
My scales are 0,1 gram precision and I'm always mixing very ( very x 3 ) carefully. I'll do some hotcoat on Monday. This time with new batch resin. Result will explain everything. Because there not....
ZABAS
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6 Years Ago
What sort of batch size are you using? Mixing or measuring errors effect different resins differently depending how sensitive they are. Some resins you can get away with being less accurate but stil...
Warren (Staff)
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6 Years Ago
Usually I was ordering 5 kg size. But now ordered 1 kg for testing.
ZABAS
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6 Years Ago
I meant when you mix up a batch to use, eg 50g, 100g etc.
Warren (Staff)
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6 Years Ago
Usually 100 to 250g. I was doing mixes up to 350g with XCR resin bought last year. Sanding after 24 hours was not very good, but never had problems with dry sanding after 48 hours. This problematic....
ZABAS
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6 Years Ago
I've got 1kg new batch XCR resin on Monday. Tried to sand it dry after 70 hours. Result is better but still insufficient. It clogs 180 and 240 grit sanding net. Resin is glossy, but if I hold warm...
ZABAS
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6 Years Ago
Seems I found an issue :). Main difference between that coatings in spring was that it was on laminate of the same (XCR) resin. These past few times it was on laminate of EL2 resin. I thought that...
ZABAS
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6 Years Ago
I highly doubt your interpretation. Epoxy doesn't really care about whats underneath. The bonding strength might be an issue, but the hardening should not be a problem. If you are 100% shure about.....
oekmont
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6 Years Ago
I agree with Oekmont, that really cant be the issue... it has to be a coincidence.
Hanaldo
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6 Years Ago
If we are in technical science discussion we should avoid that word.Because what you call coincidences, in science world are facts that were not taken into account or simply missed. I have experience...
ZABAS
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6 Years Ago
Easy. I just didn't know what kind of scale you were using. It could have been a fully resin coated old mechanical household scale as well. Another problem is often that the scale isn't placed...
oekmont
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6 Years Ago
It's also very surprising to me how cured epoxy layer underneath hotcoat layer could affect the latter. But it is coming out exactly that way. Surprising is also that MGS resin cures on cured XCR...
ZABAS
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6 Years Ago
You simply cant draw conclusions based on two results. Test it 20 times with varying batch sizes and I would probably support your conclusion, but otherwise I have worked with dozens and dozens of...
Hanaldo
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6 Years Ago
In my opinion, before you can start getting to this conclusion, you have at least to test resin from the same mix side by side on two different surfaces, keeping everything else the same. There are.....
oekmont
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6 Years Ago
Sorry to come into this late but I have ready through the thread. Warren is off at the moment so I'm checking in on some support threads. ZEBAS I think the way forward here is to simplify what's bein...
Matt (Staff)
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6 Years Ago
Hi Matt. I have no time to do this in this particular period. I'll have a trip during whole October. So now finishing started jobs. Wet sanding made it a lot longer. Maybe I'll return to this in...
ZABAS
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6 Years Ago
OK, well, I'm here to help but I'm not sure what you're looking for then at this stage. For the the record though, and to avoid confusion to other people who may read this thread, we are not aware of...
Matt (Staff)
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6 Years Ago
I'm looking for best result at this stage. My experiments will involve coating resins of some other brands from now. I'll be glad to share results if you'll be interested. If you still doubt about...
ZABAS
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6 Years Ago
If you do so, please remember to provide us the weights of each component.
oekmont
-
6 Years Ago
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