View Full Version : Birch Sealing Test -- Input Please

Eric Roach
04-18-2014, 04:18 PM
I'm testing 4 sealers to see how well they stand up to punctures (bluefish teeth, hook points, etc.) The wood is yellow birch.

The lure blanks are sealed, primed, and will be coated with lacquer paint tomorrow (I'm not clear-coating). They will be ready for the immersion test on Monday.

To simulate bluefish teeth / hook points, I'm making a jig with nails so 6 punctures are placed in the same locations and at the same depth on every lure blank.

My question is what depth do you think the punctures should be to simulate hook points & teeth in this hardwood? My initial thought is 1/8".

04-18-2014, 04:31 PM
Eric I'm sure the sealer won't go as deep as the teeth punctures. I have Bluefish punctures deeper than 1.8". I'd say 3/16". Personally, sealing the thru wire hole would be all that's needed but messy. I assume it's why we all do the entire plug. My opinion is sealing hard woods ie maple,popular to prevent cracking. Soft woods absorbing water seemed to be a concern for top waters but you really have to use that plug for a long time I would think to get it water logged. Nonetheless I seal everything w/Val oil 15min-1hour. Harder, longer. Never any issues w/ Val oil. 60/40

Eric Roach
04-18-2014, 04:46 PM
1.8"? That's like the tooth Hooper pried out Ben Gardner's hull in Jaws. :)

You might be right about the wood not being protected when punctured -- but that's why I'm doing the test; I've been using solvent-thinned epoxy for sealing for a couple years now under the assumption it was best for this purpose.

It seems to me from observing birch drink sealer that end grain (and even tapered ends) really draw in a lot of liquid, so in a way you might assume these are deeply sealed (key word: assume).

I just wanted to get an idea of what was realistic for a bluefish bite depth in birch. I was thinking 3/16" as well, but do you think they really bite that deep into such a hard wood?

04-18-2014, 05:24 PM
You know Eric, the 3/16 is in soft wood swimmers and poppers. Most of the punctures are scrapes and grooves <1/8". Your conclusions will be interesting at the least. With many builders using varying methods and times of sealing, I don't see a right or wrong method or to do or not. I do have to tell you when using BLO, I have had popular split, and maple split. Those were soaked for 1 hour and my needles cracked but still catch to this day with a 2" split. Glad I switched to either minwax clear shield or val oil mixture..

Eric Roach
04-18-2014, 06:39 PM
Val Oil is no longer available, correct? When I was looking at different sealers I couldn't find it anywhere and it isn't on Valspar's website.

04-18-2014, 06:45 PM
I'd use 1/16th in birch.
My thinking is that end grain is the issue and the water absorption from teeth holes is too small to be a factor as long as you have a good primer- color coat adhesion.

I think the hook hole is the biggest source of water intrusion and I prime them to seal them further. I don't think the through hole is a big worry since wood absorbs water from end grain, not so much from side grain (wood is like a bundle of miniature straws.....water/sealer goes in the ends easily but not through the sides of the wood tubules)

04-18-2014, 07:05 PM
Val oil was at a hardware store last year and a friend bought 10 qts. Some say it's still sold. If I can't get anymore I'll go to clear shield exterior varnish cut 60/40. Used this prior to val oil and had no issues. actually I use to prime in a couple days with this and wait 5-7 days w/val oil.

Eric Roach
04-18-2014, 07:23 PM
I'm interested in seeing what the tests show. I did a cost breakdown of these 4 sealers and several others -- the sealer I've been using is one of the most expensive, and I thought it dried the fastest but that didn't prove to be the case when I objectively tested it against the other 3.

After sealing, I dip-prime my through-wired plugs with 50% Cover Stain / 50% Naphtha to get a coat of primer on the surface of the through hole, belly hook holes and belly weight voids. If the belly weight voids are deep enough to reach the through hole, I'll dip-prime again after the weights are added and epoxied.

04-19-2014, 05:17 AM
My understanding is that there are respiratory and health issues with low viscosity sealing epoxies and xylene. True sealing using them requires about 4 coats from the technical literature and online discussions I reviewed several years back (there is a big argument on line about this somewhere on a boat building site between a manufacturer of sealing epoxy and an epoxy chemical engineer). When we seal plugs we do not completely stop water absorption, just reduce it some. The epoxies do harden the plug some, but this is a hobby and wooden plugs have existed and caught fish for decades without perfect sealing. If you are using xylene routinely in plug building I think you are unnecessarily risking your health. Hell, I've had swimming plugs that fished better when waterlogged and have actually increased the amount I weight plugs now because of it.

Eric Roach
04-19-2014, 01:27 PM
I sincerely appreciate your concern, George -- both for my safety and anyone else's reading this.

I can't argue that xylene doesn't add another level of potential danger to the plug builder, or for that matter lacquer-based detail painting (mentioned in another thread).

I had a discussion about this very thing with a plug builder after Plug Fest. He asked why I used xylene-thinned epoxy and my response was I felt it sealed best; I based that on limited subjective testing when I first started building. The problem is I couldn't objectively prove it was true -- hence the test and a re-look at my assumptions. Health risks (and the effort to mitigate them) are part of this new assessment and will factor into what changes I may make.

I'll reiterate again for anyone reading this: use of Xylene (or any VOC solvent for that matter) in the house requires the use of powerful, exterior-directed ventilation; an organic respirator and nitrile gloves to protect from skin absorption. I seal plugs with all of these precautions in place. I should wear eye protection when handling any sealer, but I don't.

GooGoo Man
04-20-2014, 07:36 AM
Hey Eric,

I can donate some val oil if you want to add it to your test.

Eric Roach
04-20-2014, 11:29 AM
Hi Glenn, thanks for the offer but I'm going to stick with the four sealers I already committed to for now.

A buddy of mine used Val Oil and I remember it staining the paint if the lures were left in the car on too hot a day (maybe he didn't let them dry long enough?) I think I'll always associate that with Val Oil.

If I move away from epoxy-sealing birch it will probably be towards spar varnish. Based on Woodbuster's 2008 testing on SOL (below), it seems spar varnish did better than Val Oil.

04-20-2014, 01:46 PM
The interesting thing about those curves is that other than BLO it seems most sealers perform about the same and only a little better than plain primer. The separation between the different curves is primarily related to variation in the starting weights. The similar slopes (wt gain over time) indicate a similar level of sealing, and it is barely better than plain primer.

Eric Roach
04-20-2014, 01:57 PM
True. I'm going to go ahead and predict my sealer isn't the super star I thought it was, and I'll probably move on to something easier, cheaper and safer.

I'm not sure what the vertical axis unit-of-measure is. Maybe grams?

Mr. Krinkle
04-21-2014, 09:19 AM
I've tried a bunch of sealers. I just use a simple sanding sealer because all the arguments of different sealers is a moot point. Also, I don't want to mess with chemicals and stuff.

The good thing about making plugs is if a plug gets water logged and doesn't swim or pop right anymore, put it on the wall of fame and make more.

Eric Roach
04-21-2014, 09:33 AM
I use Zinsser Seal Coat sanding sealer for prototypes because it dries so quickly and I'm only going to test a proto' for a few minutes. It's shellac-based so water will eventually permeate it.

It also has denatured alcohol for a solvent, which means I have to be careful with it -- it's pretty poisonous.

04-25-2014, 11:30 AM
Eric, sealing is the never ending argument of plug building. Most builders believe someone else has the secret answer and they are looking for that answer. Most of what I know has to do with carpentry and woodworking rather than sealing, but you should always look at the basics.

1.) Mositure will always interact with wood, there is nothing we can do to stop this. Wood was made to take moisture from the ground to the leaves. Forces beyond are control are at work here.
2.) End grain is where wood will absorb moisture. Long grain will not absord moisture. I'm sure everyone has heard the straw analogy.

I build with pine, basswood, birch, maple, ayc, red cedar and white cedar. I have tried many many sealers and to be honest, they all pretty much work the same. Some are cheap and quick, some are expensive and lengthy and some will probably kill you from long-term exposure.

The best advice I received from a commercial plug builder was the following "take a finished plug and weight it. Next submerge it in a bucket of saltwater for one hour and weight it again. If you do not have weight gain you are good to go." This plug builder is long gone but this advice is very good.

Eric Roach
04-25-2014, 01:20 PM
...sealing is the never ending argument of plug building...

Indeed it is -- that, and "the perfect" clear coat.

Lots of opinions out there. Lots of assumptions as well. This test is a hassle, but I'm glad I made the effort to objectively see for myself. So far, there aren't any drastic performance standouts.

I'm about to take the 30 test lures out of the saltwater for the hour 18 weighing.

I'll post the test results in a new thread.