Loctite E-90 FL Hysol really good?



We noticed that you are using the E-90FL Hysol adhesive to glue the various parts of the rover together. When we checked the specs of the adhesive, they say it's partially soluble in water. Does it hold really well for you? It also seems to take much longer to fully cure and dry out than they say. We have to let the parts sit for over a day to get them fully glued.





I haven't experienced any trouble with it being soluble in water, but I have noticed that it takes longer then described to cure if it is left in a cool environment. The slow cure time is good because it allows all the air bubbles to escape and lets epoxy creep into all nooks and crannies. We've tested this over many days in salt water down to pressures of more then 20m, but let us know if you learn more about its performance or have recommendations for a better alternative.

Thanks for the input!



Hi Eric,

We are using this product in our lab to "weld" acrylic:


WeldOn has the following advantages compared to Hysol:

1. It's tensile strength is 17 N/mm2 while Hysol reports 13 N/mm2 if I remember correctly.

2. It's cures within seconds to the point of holding the parts together. Within the next hour, it cures completely.

3. It's transparent - looks better after applied.

4. It doesn't glue parts together, it literally welds them together, so it is completely water non-soluble.

Other than that, I think they both do their job and either of them can be used. WeldOn seems to have some advantages though. The fast curing can be a disadvantage for beginners because it doesn't give one much time to move the parts around into their perfect positions as it dries up pretty fast. Other than that, it's a great alternative to Hysol.





There has been a misunderstanding! Yes- we use acrylic cement (in fact, we use WeldOn Brand) to attach all the laser-cut pieces of the ROV. It works great. The Hysol E-90FL is only used for potting the wires that pass through the endcaps. Sorry for the confusion!

We're also trying to figure out the best way to send both of these adhesives in our kits since neither of them are easy to come by at local stores, and the kits don't need very large quantities of either. Our initial plan has been to just put 10 or 20 ml of acrylic cement in a syringe which we can cap off and put in the kit, and to find some sort of marine epoxy that comes in a ready-to-use package that has its own mixing tube instead of using E-90 which requires a special dispenser gun and additional tubes.

Any ideas?



Damn. Then we screwed up :). We used the E-90 adhesive to glue all the parts together. Looks kinda ugly because our entire acrylic is transparent (not blue like yours), but it seems to work. It should be fine, I hope. I guess we'll get some paint that covers acrylic well and paint the rover.

Since you intend to use E-90 only for potting the wires that pass through the endcaps, you don't need to send much of it and I think your syringe idea should work just fine. As for WeldOn, maybe you could get a set of smaller containers, but the same kind as the ones that the adhesive comes in and distribute it in those. You could also add in a syringe and a pipet to fill the syringe easily. We do it that way.

So I think this also answers my other thread question about how to prevent water from leaking in through the wire outlets in the endcaps. What did you make the endcaps from, though? They are not a part of the autocad drawings.

Also a small reminder, when you can, please, try to post images of the openrov wiring as a sanity-check/guide for us.

Thanks a lot,




because I can not find E-90 I'm searching for some alternate stuff. What do you think, will something like this work: http://www.conrad.de/ce/de/product/241016/LOCTITE-5910-Dauerelastische-Flaechendichtung-Schwarz-50-ml

It is some kind of silicone.

Regards, Reimar



I’m not sure if that will work, but what I’d recommend if you can’t get E-90 is some other type of two-part, slow curing, waterproof epoxy or potting compound. If you go to a boating store, they may have a 2 hour marine epoxy the could work. We haven’t really tested very many other epoxies, so if you do some testing of your own, let is know how it works out!



Hi Eric, Just ordered my OpenRov kit, and is searching for acrylic cement and epoxy. But I have a question about the epoxy. You mentioned that long curing time is good, because of air escape and that it will fill into small gaps. But I do have a vacuum pump with a chamber, used for vacuuming when molding plastic. Would it be a good idea to put the endcaps in the vacuum chamber during curing prosess?