buffingtonwa Posted June 23, 2013 Report Share Posted June 23, 2013 Like many of you on this site, I was a devout fan of Devcon 2-Ton (D2T) epoxy for numerous processes of lure making. I used it for gluing in lexan lips, gluing the 2 sides of my lures together (I make CNC milled 2-part crankbaits), and sealing/finishing. However, this year, I discovered that the chemical composition of D2T actually makes lexan bittle and prone to breaking at the point it goes into the bait, as well as becoming brittle itself once and being easily cracked after a week or so after curing (the brittleness of D2T can actually make the lips crack free of the lipslot and be easily pullled out). The cracking can also make paint chip away from the surface of wooden baits more easily...and other nasty things can happen. After discovering this, my partner and I began a long (about 5 month) testing period with other chemicals. We tried all sorts of epoxies and polyurethanes from eagerplastics.com, flexcoat products, CA products, marine adhesives, moisture cured urethanes, polyurethanes, etc (probably over $1000 in diff chemicals). The only ones we did not test that I know of were UV cured. What we found was that for gluing parts, including lexan to wood, the flexcoat epoxy (not finish) works best for us. There is no lip breakage from chemical interaction at all with this product and it doesn't become brittle like D2T. For a finish, we've decided on the flexcoat UV rod finish works best. It is a bit tough to mix without getting bubbles, but the end results are hard, durable, and provide a bit of flex for when those errant casts send your bait into a pile of rip rap (or if you're clumsy like me, you bang the lure on your trolling motor while casting). We seal with propionate .For those of you who do detailed baits, like we do, propionate helps to keep the detail of the bait until you are ready to paint (unlike 2-part seals which smooth everything out), and then a thick coat of Flexcoat UV encapsulated the detail and creates a really cool effect on the bait. Anyway, I hope this helps all you lure makers, expert and novice alike! Full disclosure: I have no affilitation with Flexcoat or any of their products other than being a converted customer! Quote Link to comment Share on other sites More sharing options...
BobP Posted June 23, 2013 Report Share Posted June 23, 2013 Thanks for the info. I'm not an epoxy chemist but would appreciate a little more info since I've been using Devcon for a long time and never noticed the brittleness effect you report. Can you describe the chemical reaction that takes place between Devcon and polycarbonate? And how is Flexcoat UV different in its chemical composition from Devcon? My impression was that epoxies differ mostly in the hardener agent used, and that the epoxy resin was pretty much the same across many brands. You aren't the only ones who like the Flexcoat UV for topcoating baits. One of the better custom wood bait makers here on TU also uses Flexcoat. Quote Link to comment Share on other sites More sharing options...
bluetickhound Posted June 24, 2013 Report Share Posted June 24, 2013 (edited) Any possibility that you may have just gotten a "bad" batch or has this been an ongoing problem? I ask because I have used D2T in the past with great results. I have never used flexcoat but will definitely give it a look see... Currently I'm using ACC as a topcoat and love it but I don't use it to glue anything together.... Usually its D2T or the loctite 5 min epoxy.... Edited June 24, 2013 by bluetickhound Quote Link to comment Share on other sites More sharing options...
buffingtonwa Posted June 24, 2013 Author Report Share Posted June 24, 2013 Bob - I don't know anything about chemical compositions so I can't really speak on what causes the above listed problems, but when one of my friends was using my baits, he had issues with the devcon breaking free of the lexan and lips pulling out. Once that happened, I went back and did tests. In addition to the lip breaking free from the bait (this is a brittle factor that most other topcoats don't have since their shore harness isn't as high as the D2T, which is 83/84 vs 80 on most of the other known finishes), I found that the D2T makes the lip more susceptible to breakage. It doesn't crack or snap, but tends to tear like it's been weakened. If you've ever dipped lexan in propionate and then twisted it, it's something like that, it's definitely like something in the D2T is breaking down/weakening the lexan. Honestly, unless you really tried to do this, it's not something most people might notice or even attribute to the epoxy, but when I had these problems and investigated more thoroughly, that's what I found. Also, to combat the lip from breaking free, we've since started drilling holes in the back end of our lips so there is a more mechanical bonding than there was before. Bluetick - there are 2 different products from flexcoat that we use. One is epoxy, that we use for its adhesive properties, i.e. to glue baits together/lexan lips into place. The other is Flexcoat Ultra V rod finish, which we use as a lure finish. I know there are extensive threads on this site about different finishes, and we chose this one for it's hardness/flexible properties, as well as the UV stable claim the company makes. I've used the ACC (and E-tex) as well, though I didn't put that in above thread. They are both good finishes. The only problem I have with those is the well known "multi-coat" requirement, otherwise, they are both good products that I've not found any real problems with, so far. Quote Link to comment Share on other sites More sharing options...
hazmail Posted June 24, 2013 Report Share Posted June 24, 2013 (edited) For What It's Worth I have samples of all sorts of Epoxy & others dating from about 2007-8. As 'Buffington' says, Devcon does become very brittle, very fast- all my samples are 'pooled' epoxy on 'duct tape' so can be bent/ snapped very easily, all the others, inc most rod finishes, Flexcoat, Etex etc can still be bent/ twisted after 3-4 years, yellowing is minimal (none stored in direct sun)---Devcon snaps like glass after about 48hrs. I also have a 'puck' of DN Clear ("Pelucid") which is 2" dia X 3/8" thick, which set about 4 years ago and it still has some flex. Have not yet had the 'sheering lip' problem with Devcon though. Pete Edited June 24, 2013 by hazmail Quote Link to comment Share on other sites More sharing options...
Don-Art Posted June 24, 2013 Report Share Posted June 24, 2013 For reasons unknown to me I have not encountered this problem. I believe that it probably revolve around the hardener portion.I would believe that an epoxy with a 2:1 ratio,might be a better fit when bonding Poly carbonate.Also thinning the epoxy with solvents could potentially cause issues with Poly carbonate. Quote Link to comment Share on other sites More sharing options...
BobP Posted June 24, 2013 Report Share Posted June 24, 2013 I cut a couple of slots in the back of Lexan lips to provide extra glue surface and can't remember a lip breaking free using that method. I've smashed a Devcon coated balsa bait on the boat motor and had it chip off a large area of finish. Would that have happened with another brand of epoxy? Don't know. But I accept that a crankbait can be damaged by extreme abuse. I've continued to use Devcon Two Ton because I like its relatively quick cure time and appearance. Frankly, I haven't tried Flexcoat UV because, at $23.35 for 8 oz, it is almost twice the cost. I'm certainly not trying to run down Flexcoat UV. This isn't the first report that it works great and I accept your finding that it has better physical properties than Devcon based on your experience and experimentation. One thing that doesn't receive much attention: epoxy has a minimum film thickness required to form a strong bond. If your lip slot is tight and almost all the epoxy is wiped away when you insert the lip, you can't expect a strong bond. I try to cut mine so there is slight if any drag when the lip is dry fitted into its slot. Actually, I don't use Devcon or any other liquid epoxy for lips anymore, opting instead for the slow cure version of Rod Bond paste epoxy. It gives me several hours before the epoxy begins to significantly harden, which is nice because I tend to screw around a lot with the lips on a batch of baits to get them aligned and I don't like to be in a hurry when I do it. Quote Link to comment Share on other sites More sharing options...
Don-Art Posted June 24, 2013 Report Share Posted June 24, 2013 I also cut bonding slots in my crank bait lips. I'm in this for myself/family and friends.So I am never in a big hurry to get them done. There's a fine line between enjoying something and not.I don't really want to cross that line and lose something along the way. Last night I took a pliers to the lip of one of prototypes made from Cedar that had been bonded in with D2T and after a bit of a struggle it broke free. But it took the cedar base material with it. I should also mention that I make all of my own lips from poly carbonate sheet stock,not sure if that would have anything to do with it or not? I will continue to watch to see if I have any of the issues appear on any of my baits. I never keep a large amount of D2T around so if I decided to change it wouldn't be a real big deal. Quote Link to comment Share on other sites More sharing options...
hazmail Posted June 25, 2013 Report Share Posted June 25, 2013 " Actually, I don't use Devcon or any other liquid epoxy for lips anymore, opting instead for the slow cure version of Rod Bond paste epoxy. It gives me several hours before the epoxy begins to significantly harden, which is nice because I tend to screw around a lot with the lips on a batch of baits to get them aligned and I don't like to be in a hurry when I do it. " Just what I'm looking for Bob, time is on the lure's side these day's, now I need all the time I can get for bib alighnment-- There is nothing worse than cliping one on in the boat and immediatly realizing the bib is off centre---how come you see it now , but not when you are glueing them up in the shed . Pete Quote Link to comment Share on other sites More sharing options...
bass100 Posted June 25, 2013 Report Share Posted June 25, 2013 D2T does not make lexan brittle. Lexan is very flexible and D2T is not as flexible so the epoxy will break off of the lexan every time it bends. D2T works great on anything that is less flexible than it is. Quote Link to comment Share on other sites More sharing options...
Don-Art Posted June 25, 2013 Report Share Posted June 25, 2013 Bass I would have to agree with you.I believe that an epoxy with a bit more flexibility may be the ticket.I also like to use a wider saw kerf than my lip thickness. It also allows for any expansion or contraction. Knowing that both materials the lip and the lure body will expand and contract at different rates,it only makes sense. So a flexible low shrinkage product like the Rod Bond that Bob had mentioned sounds like a good fit for the application. Quote Link to comment Share on other sites More sharing options...
BobP Posted June 27, 2013 Report Share Posted June 27, 2013 Another thing I like about Rod Bond is that it does not turn brown over time. I tried 5 Minute Devcon when I first started and soon saw that I didn't want to use it anywhere on a lure that might show because it will eventually turn a dark ugly brown from exposure to UV rays. I still use it to glue lure halves together when thru-wiring but that's all. Quote Link to comment Share on other sites More sharing options...
Skeeter Posted July 6, 2013 Report Share Posted July 6, 2013 Devcon does not make Lexan (Polycarbonate) brittle. You have something else going on there causing your problem. Skeeter Quote Link to comment Share on other sites More sharing options...
fatfingers Posted July 6, 2013 Report Share Posted July 6, 2013 I have musky baits, some as old as 8 long hard seasons, with D2T in the lips slots and have not had even one fail. I've also experienced no problems using it with a number of different brands of polycarbonate. You need to properly install the lip by both slotting it and drilling two holes within the area that will be covered by the bait. You also need to "rough up" that same area with a sanding drum on a rotary tool so the epoxy has something to bite onto. There may stuff better than D2T but only in matters other than raw strength. That stuff is tough as nails. Quote Link to comment Share on other sites More sharing options...
Skeeter Posted July 7, 2013 Report Share Posted July 7, 2013 (edited) Are you sure that you have true polycarbonate? What you are describing sounds like acrylic to me. It can become brittle, especially in cold water. Many places try to sell acrylic and call it Lexan. Lexan is just the trade name given to polycarbonate by General Electric. They invented it. There are also different grades of polycarbonate. Most if it has fillers in it. The purest grade is used for bullet proof glass. 12 yrs. ago that was $70.00 a square foot. I have been making crankbaits for 14 yrs. and use 1/16th inch stock. I have never had a polycarbonate lip break. That is why I ask. Skeeter Edited July 7, 2013 by Skeeter Quote Link to comment Share on other sites More sharing options...
Seeking 56 Posted July 7, 2013 Report Share Posted July 7, 2013 (edited) I've had a Makrolon polycarbonate 1/8'' thick lip break in half on a lure I built for a guide. It was a horizontal break. The shape of the lip and angle closely resembles that of a Stalker. Cold weather and the lure being slapped against the water to remove weeds was the cause according to the guide. I too didn't think polycarbonate could break as it's never happened to me and I make my lures pound bottom. According to my polycarbonate supplier it's not supposed to break. For all I know it was probably stepped on. s56 Edited July 7, 2013 by Seeking 56 Quote Link to comment Share on other sites More sharing options...
