Vacuum sealing saltwater plugs with water based polyurethane/water mix

[George Herman]

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.

[BobP]

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?

[George Herman]

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.

[mark poulson]

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.

[JD_mudbug]

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.

https://www.youtube.com/watch?v=CWflb2KILIM&t=768s

 

[George Herman]

Thanks Mark,

I have been using your method prior to this experiment. It does work and l may end up just dealing with the fumes but I work in a cancer center and that seems foolish ( smoking a cig as I'm typing this) I just want my grandson to be able to hand one of these lures to his grandson.

[George Herman]

JD,

Once again thanks for sharing your knowledge. I watched the video and realized I can add an ink/dye and experiment with time and absorbance and possibly get a clue and weigh each and see if I can find a happy medium. Thanks for any and all insights.

[ravenlures]

George

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. 

Regards

Wayne

[George Herman]

Just as a follow up in case anyone is curious. I tinted my hardner red and poly green. The hardner hardly absorbed at all with a ten minute dunk  and after 12 hours investment in time the vacuum method achieved the same results. Had to see for myself. 

[George Herman]

[JD_mudbug]

Is that the maple you were using?

I got penetration when submerging 1-1/8" poplar dowels in the Minwax hardener. I hand carved and sanded them to a rough finish with 60 grit before dunking.

I am surprised the vacuum didn't get better results.

[George Herman]

Yes it is maple. I was shocked at  the results. From what I've read and popular opinion both were wrong. You watch the bubbles on a dip with the hardner and you expect at least a little depth but it didn't happen. The vacuum results dropped my shoulders big time. I sucked out air for four solid hours and it's still superficial. I get my wood free from a high end cabinet shops cutoffs. I would like to utilize it. Besides being free, it's fully finished on all sides. Because my target fish are stripers, I know toothy blues will hit the lure (if it works) too. Combine that with hook rash and I estimate at the bare minimum I need at least a 16th inch of protection. My solution is yet to be found. Next up is an hour soak in hardner. I will rough sand one and finish sand the other and compare. As far as the vacuum method, going to try different water/poly ratios. 

[mark poulson]

You might try heating the blank in an oven or a microwave before you dip it.  My friend Barry Starud, of Barry Baits, does that before he dips in a penetrating epoxy, and he gets really good results.

I dip my red cedar lures in the wood hardener, and it does penetrate and harden, but I've never cut one open to see how far it penetrates.  I make sure my lures are fully shaped and sanded, and that all the holes, for line tie, hook hangers, and potential ballast, are drilled before I dip them, and all of the holes are really hard afterwards.  Cedar is a softer wood than Maple, so it may depend on the wood you choose, too.  

[JD_mudbug]

I thought the same thing about the type of wood being a factor. I tried to make a lure out of a hickory hatchet handle and the hardener did not seem to penetrate it. I had one made from a poplar dowel. I cut the V joints after the soak in the hardener and it looked like it penetrated an 1/8 to 3/16th of an inch.

[barrybait]

I have a 7" wake bait I made out of balsa that was very lively due to light weight and the fish couldn't stand it.  It fished very well and soon the fish won and now it is hanging in my shop with a big chunk out of it.  So now I am in the process of finding a happy medium of slightly stronger wood and tougher coatings so that they will last longer. I am making a 7" Golden Shiner of my own design and 7" and 9" knock offs of the AC Plug Minnow.

I have given up on the lighter weight balsa (7-8 lbs/cubic foot) and am currently making these lures out of graded balsa, medium weight (10-14 lbs/cubic foot),  white pine, and western red cedar.  I shape everything and cut the bill slot and vee notch and drill all my hardware holes then I epoxy my hook hangars in so I have something to hold on to and or hang it from.  Then I heat them up in a food dehydrator that has a thermostat which I set to 140F.  Then I coat them while holding them by the hook hangars with needle nose vise grips.

Brush ready, I dip the ends in my mixing cup of Tap Plastics slow cure epoxy (Basically Clear Penetrating Epoxy) and brush everywhere I can't dip.  I know it draws it into the end grain because I have to keep wetting it as it draws in.  That don't happen on the sides.  I don't think anything you use is going to penetrate the sides.  Unless there is end grain access you are not going to get sealer to penetrate.  However, everywhere you are tapering the shape of the lure exposes end grain which draws in the sealer you are using.

If you want more protective coating on the sides you are going to have to apply more coats of sealer/top coat whatever you are using to get the thickness you need and/or expose the wood's end grain.  JD_mudbug's technique (a couple of post above) of sanding with 60 grit will help by exposing end grain on the sides especially by sanding across the grain will allow the wood to hold more sealer.

I forgot to mention that I overdrill all my hardware holes and I don't have any blind holes.  That is, if the line tie, hook, or hinge holes don't go all the way through, I drill a vent hole.  Also, I tried Minwax wood hardener on one of my two cedar lures and didn't find any improvement.  Certainly not enough to justify the extra step.