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George Herman

Vacuum sealing saltwater plugs with water based polyurethane/water mix

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Anyone have experience with this method? I'm winging this and know I really should ask for wisdom, just don't know where. So far made some test runs with about 10/90 percent water/poly. Pulled full vacuum for about 15 minutes until most bubbles popped. First batches l pulled out about an hour bath, I do think they should stay in a bit longer. Questions: Does anyone leave them overnight? Is it recommended? How does it effect buoyancy? I'm working with maple. Any help would be much appreciated.

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George, I tested water based polyurethane as a clear coat a few years ago.  It failed miserably so I’d be leery of using it in any crankbait application.  It will definitely reabsorb water after drying (assuming you can actually get it to dry without a kiln)  It will also cause wood to swell, unlike most oil based products.  So, if it can reabsorb water and cause a bait to swell up, what utility does it have?

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Thank you for your reply. I'm not sure I made it clear what l'm attempting. l'm trying to waterproof the internal structure of the wood by pulling out air and hopefully replacing it with poly. Trying to avoid the alternative mineral or linseed oils. This method I can safely do in my basement over the winter. I haven't had a problem with it drying. After the poly seal, I sand, paint, and clear coat with true coat. I do have concerns with seepage and swelling and would like to see if anyone that uses this method has a tried and proven way of doing it. Thanks again, any and all help greatly appreciated.

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You might try Minwax Wood Hardener instead.  It is designed for residential painters, to harden wood that has begun to rot, so they can fill in the bad/missing part with Bondo, and then paint.

It is drawn into the grain, especially the end grain, and makes the wood waterproof.  I dip my wooden baits for ten seconds, and then hang them to dry/cure, with a fan blowing the fumes away.

After it off gasses it's solvent, you can finish sand, prime, and paint.  Then use your topcoat of choice.

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I have never done vacuum sealing so I don’t know if this will help. Like Mark, I have sealed with Minwax Wood Hardener. That stuff does penetrate deep into wood if you submerge the wood in it for a while. I used it on baits made of Western red cedar and poplar. These were 7 to 9” baits that were 2 to 3.5 oz. They would gain from anywhere from .15 to .35 of an ounce with dunks over 15 minutes. Prolonged dunks in the hardener did affect the buoyancy slightly. The baits sat a bit lower in the water than similar baits sealed with superglue. I suspect it made them dive slightly deeper. My baits were wake baits and shallow diving jointed swimbaits. It did not affect the action that I could tell, which may be in part due to the large size of the baits and type of wood. Cedar and poplar are more buoyant than maple.

Seepage was a big problem with the wood hardener on any dunk besides a brief one. The complete drying/off gassing time depended on the length of the dunk. I submerged a bait overnight once. It took 10 days before the paint stopped getting blisters. I don’t do prolonged dunks anymore because I have to let baits sit for so long just to be sure they were safe to paint. I would put a coat of Rustoleum 2x flat white paint + primer rattle can on the baits after I thought they were dry and let them sit again for 1-2 days to see if any paint blisters developed before continuing to work on them. I suspect with the penetration you will get with vacuum there could a prolonged period of seepage.

I remember some posts years ago from a striper lure maker who vacuum sealed lures. I could not find the posts. His baits were also large baits, similar to Gibbs lures. He was using 20% distilled water and 80% water based polyurethane. It did add some weight but did not seem to affect the lure’s action. I believe his baits were made from poplar dowels. He was the only person I remember trying it. In addition to worrying about a change to a wooden lure’s buoyancy and action, the question is whether it is worth the extra effort (and additional equipment if you don’t have it) over the usual sealing methods and whether it is better to just use a casting resin or PVC. If you are vacuum sealing wood to pull all the air out of wood and replacing it with a sealer you are essentially changing a fundamental characteristic of wood (the air inside it) and essentially turning it into a resin-like product.  Vacuum sealing never seemed to catch on as a way to seal baits.

Maple is denser than the 2 woods I use. You would also be removing more of the air with vacuum as opposed to dunking. I think it would have some effect.  I would weigh the wood before you seal and weigh it again after you have sealed to see if you gain more than 10% in weight. Maybe you could make some identical baits, vacuum seal some and seal some with superglue. After the baits are sealed and hardware is installed, you could compare how they sit in the water and their action.

There are some videos on YouTube on vacuum stabilization of wood. I don’t know if these would provide any useful information. They all seem to use an epoxy like product called Cactus Juice.



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If it were my choice for a saltwater lure, I would use a resin poured lure or a PVC and all this worry about water penetration would be over, and get to testing the lure out and catch some fish. I realize that sometimes we try different methods but sometime we just get stubborn (like myself) and finally go to a proven way. But if you may then go to it. 



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