|
oekmont
|
|
|
Group: Forum Members
Posts: 550,
Visits: 27K
|
If you do so, please remember to provide us the weights of each component.
|
|
|
|
|
ZABAS
|
|
|
Group: Forum Members
Posts: 16,
Visits: 30
|
+xOK, 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 any incompatibility between XCR and different brands of epoxy resin used underneath. If anything similar is ever reported or if you get chance to conduct the test described earlier and it does produce different results across the samples then we would be happy to investigate further. 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 total incompatibility of EC epoxies to MGS epoxies then I'll make a samples just for you in November  .
|
|
|
|
|
Matt (Staff)
|
|
|
Group: Forum Members
Posts: 680,
Visits: 1.9K
|
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 any incompatibility between XCR and different brands of epoxy resin used underneath. If anything similar is ever reported or if you get chance to conduct the test described earlier and it does produce different results across the samples then we would be happy to investigate further.
Matt Statham
Easy Composites / Carbon Mods - Technical Sales
|
|
|
|
|
ZABAS
|
|
|
Group: Forum Members
Posts: 16,
Visits: 30
|
+xSorry 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 being tested, isolating as much as possible. The conclusion that you have come to regarding cure inhibition caused by different brands of cured epoxy substrate seems highly unlikely but could be tested for in a controlled way by making up some small samples: - I would make up 4 petri-dish sized samples (ideally in an inert thermoplastic container, such a polyproylene) with accurately weighed and mixed XCR, EL2 and the MGS L285+H286 at a 2mm depth in the bottom of each. One sample with no resin in (making up the four samples).
- Cure all resins off fully in the same environment (a temperature controlled oven at 20°C would be ideal).
- Make sure the samples should be fully cured (according to their datasheets, with respect to their cure time/temperature).
- Key the surface of the three samples and then pour a 1mm coating of correctly measured and mixed XCR over the top of the three cured and keyed resin samples and into the remaining empty dish.
- Cure all samples together back in the 20°C oven until fully cured.
I believe this would quite quickly provide results that would give a good indication as to whether there is any substance to your suspicions and, as unlikely as it seems to me, I would certainly be happy to remain open-minded and investigate further if you do find a difference across the samples. For the results to be genuinely helpful though it would be essential that the mix ratios were correct (helpful if you give us the actual grams used) and that the cure state was complete for all resins. Before they reach full cure there is the potential for a reaction which could more plausibly inhibit or affect the cure of a resin applied over the top.
I hope this helps and look forward to working with you to get to the bottom of this. 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 November if I won't find another solution. Currently I do not have MGS because I switched to EL2 a year ago when saw it was incompatible with XCR.
|
|
|
|
|
Matt (Staff)
|
|
|
Group: Forum Members
Posts: 680,
Visits: 1.9K
|
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 being tested, isolating as much as possible. The conclusion that you have come to regarding cure inhibition caused by different brands of cured epoxy substrate seems highly unlikely but could be tested for in a controlled way by making up some small samples: - I would make up 4 petri-dish sized samples (ideally in an inert thermoplastic container, such a polyproylene) with accurately weighed and mixed XCR, EL2 and the MGS L285+H286 at a 2mm depth in the bottom of each. One sample with no resin in (making up the four samples).
- Cure all resins off fully in the same environment (a temperature controlled oven at 20°C would be ideal).
- Make sure the samples should be fully cured (according to their datasheets, with respect to their cure time/temperature).
- Key the surface of the three samples and then pour a 1mm coating of correctly measured and mixed XCR over the top of the three cured and keyed resin samples and into the remaining empty dish.
- Cure all samples together back in the 20°C oven until fully cured.
I believe this would quite quickly provide results that would give a good indication as to whether there is any substance to your suspicions and, as unlikely as it seems to me, I would certainly be happy to remain open-minded and investigate further if you do find a difference across the samples. For the results to be genuinely helpful though it would be essential that the mix ratios were correct (helpful if you give us the actual grams used) and that the cure state was complete for all resins. Before they reach full cure there is the potential for a reaction which could more plausibly inhibit or affect the cure of a resin applied over the top.
I hope this helps and look forward to working with you to get to the bottom of this.
Matt StathamEasy Composites / Carbon Mods - Technical Sales
|
|
|
|
|
oekmont
|
|
|
Group: Forum Members
Posts: 550,
Visits: 27K
|
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 too many other things that can interfere in the process.
If it was bonding to the surface, I would totally see your point there.
In my opinion epoxys are really reliable. If I done everything right it never failed me. Bonding, pot life, curing, strength, every aspect. So far every batch behaved just as the one before. and the specs were always right. the only thing you have to get right is the mixing ratio, the mixing itself, temperature and the underground preparation in terms of bonding/releasing.
Polyester however is much less reliable, wich is why I do most of my moulding in epoxy, too.
When somebody comes to me with incurred epoxy, in the most cases, they mixed everything by eye, or their interpretation of 100:30 is "out of every 100 units, 30 should be hardener", wich is what we would call 70:30.
|
|
|
|
|
Hanaldo
|
|
|
Group: Forum Members
Posts: 2.5K,
Visits: 28K
|
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 different types of resin including in the customer support sector. I have had many many people bring products back and say it doesnt work, insisting that they didnt make a mistake and that there is something wrong with the resin - not once has that ever been the case. It is always one of three things - off ratio, poor mixing or low temperature. Other than that, the resin that comes back to us always works when we do a test ourselves. In 19 years, the company I work for has never ever had a single batch of epoxy resin that didnt go off due to a fault of the resin. Polyesters, vinylesters, polyurethanes, silicones - sure, all of these go wrong from time to time. But not epoxy.
I'll rephrase my previous statement; its possible it isnt coincidence. But I dont think you have anywhere near enough data to prove anything just yet, and I think it would be a shame for you to drop a good product from an excellent company based on two results.
|
|
|
|
|
ZABAS
|
|
|
Group: Forum Members
Posts: 16,
Visits: 30
|
+xEasy. 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 levelled and flat. I just wanted to to help you with the usual things that come to my mind if something like that happens. It never really happend to me, although I've been doeing this for years with a ton of different systems, but it happened multiple times to my father, who sometimes isn't that accurate. So my first guess is always the mixing ratio. And most times this is the problem. if done a serious amount of science in my life, and "facts" is the single word to really use with care. Especially without isolating countless variables, don't change anything, repeating something only twice, and than just pick one variable to be the issue. This is the opposite of a "proven fact" (well, with only one repetition it would be). What catches my eye is that, for what I read from your last post, you made 5 trials, and 4 did not end up well. That seems like a serious problem. Don't get me wrong, maybe it is the different resin, but from all the hundreds of things I can think of, this seems to at the very very low ending of plausibility. The laminating resin is very inert once cured. I would absolutely eat from it (maybe not with knife and fork because of scratching). The are no fluids left, so why should it contaminate the, in a molecular perspective, infinite thick layer of resin? In addition all epoxys are called epoxys, because the reactive groups are the same. If you really know what you are doing, you could even swap the hardeners of most resins. #amineequivalent I have seen lots of different epoxys fully cure on lots of different surfaces. Including unprepared rock, wood, slightly oily metal, and even just dirt. And under water, too. This are some surfaces you are regularly told to not to use epoxy on. and it always cured on my work bench and my workshop floor. I am just saying, that if I were you, I would look for the problem somewhere else. 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 resin layer perfectly. But XCR and also EL2 on cured MGS - no way. My conclusion would be that XCR ( and also EL2 ) is sensitive to some additives used in cured resin. And sensitivity should be very high, because it reacts to micro doses.
|
|
|
|
|
oekmont
|
|
|
Group: Forum Members
Posts: 550,
Visits: 27K
|
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 levelled and flat. I just wanted to to help you with the usual things that come to my mind if something like that happens. It never really happend to me, although I've been doeing this for years with a ton of different systems, but it happened multiple times to my father, who sometimes isn't that accurate. So my first guess is always the mixing ratio. And most times this is the problem.
if done a serious amount of science in my life, and "facts" is the single word to really use with care. Especially without isolating countless variables, don't change anything, repeating something only twice, and than just pick one variable to be the issue. This is the opposite of a "proven fact" (well, with only one repetition it would be).
What catches my eye is that, for what I read from your last post, you made 5 trials, and 4 did not end up well. That seems like a serious problem.
Don't get me wrong, maybe it is the different resin, but from all the hundreds of things I can think of, this seems to at the very very low ending of plausibility. The laminating resin is very inert once cured. I would absolutely eat from it (maybe not with knife and fork because of scratching). The are no fluids left, so why should it contaminate the, in a molecular perspective, infinite thick layer of resin? In addition all epoxys are called epoxys, because the reactive groups are the same. If you really know what you are doing, you could even swap the hardeners of most resins. #amineequivalent
I have seen lots of different epoxys fully cure on lots of different surfaces. Including unprepared rock, wood, slightly oily metal, and even just dirt. And under water, too. This are some surfaces you are regularly told to not to use epoxy on. and it always cured on my work bench and my workshop floor.
I am just saying, that if I were you, I would look for the problem somewhere else.
|
|
|
|
|
ZABAS
|
|
|
Group: Forum Members
Posts: 16,
Visits: 30
|
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 experienced twice last year that XCR resin does not cure on MGS resin. If to be precise, it was MGS L285+H286 ( it's stable product itself, I used it since 2012). After first time I called it coincidence. After second it became proven fact . It's not very funny to scrub resin off and then try to wash it using acetone. So it stays in memory for long. What about recent issues. I had two SUP boards. Both were laminated using EL2 resin and then coated using XCR resin. In both cases XCR did not cure properly resulting in sanding problems. After first I thought it maybe coincidence . After second I've written to this forum. I had one surfboard project at the same time. Laminating was made using XCR and then coating using XCR. Cure perfect, no sanding problems . I do sanding using sanding machine with MIRKANET. Usually it is hard to clog because there is dust suction through whole surface. If it clogs that means sanding material is too soft for dry sanding. oekmont, all scales I'm using are 0,1g precision. You must agree that when mixing batches of 150-250g the precision is around 0,2%
|
|
|
|