MarkR

What is the general thickness of the ETEK top coat

16 posts in this topic

Hi all, I am new to the site and hard bait building. Last year I started lure making but stuck to easier lures like bucktails, spinnerbaits and some other hair/fur type lures. This off season I have decided to try my hand at some deep and shallow crankbaits and some dive/rise jerkbaits. These are for personal use only, I may give the odd one to a friend but I have no intention of selling them. I have spent the last several months reading a lot of material, includign a lot on here, and trying to figure out my plan of attack and have finally come up with the following process.

1) I will be using primarily cedar, western red and eastern white. Both easily accessible and reasonably priced. At some point I may try some different types of wood but chose cedar as a start.

2) I will seal the bait with a couple dips in sanding sealer. Sand with fine paper after it dries.

3) Apply a coat of primer paint.

4) Paint the lures with acrylics. To start we will just be using brush on paints, we used to paint for a hobby so we have the paints and brushes etc. In the future we will look into an air brush.

5) Insert dive bib on crankbaits or dive tail in the jerkbaits. I will be using 5 or 6mm Lexan for my dive bibs, and I have dive tails from lure parts online.

6) Coat with a couple layers of ETEK as the clear coat. I will build a turner.

I will be using primarily through wire construction, by cutting the lures down the centerline and glueing the two halves back together once the internals have been put in the correct places. I may build a couple with screw eyes just as test specimens.

I have found the template for the Grandmas so as a starting point I was going to try some minnowbait style lures, thickness of baits will likely vary from the originals so I plan to modify my lip accordingly, I acknowledge this will be a trial and error process. As it will be with all crankbaits in determining the best bib shape, angle, size, line tie location etc.

With all this said there are still a couple of factors I am racking my brain around and was hoping some of the builders here could provide some insight.  

Q1) Any recommendations on a decent primer paint to use. I am not sure I even need this, maybe a white base coat will be sufficient over the sealed bait. If I need primer specifically I would prefer a brush on or dip as I do not have the room to be spraying aerosol paint cans.

Q2) What is the avg thickness or weight addition of the clear coat when using ETEK. I will likely do 2 layers, more if needed, and I know this will vary by bait size and builder but is there a general thickness I could use to try and estimate the weight I will be adding with the clear coat. Off the top of my head I was thinking around 3 mm additional thickness, on each side. In my view determining the weight addition by the epoxy, which on a 10-14" bait can be a few oz, is more important than the actual increase in dimensions. I figure the extra size can be overcome with a bigger bib, only time will tell with some trial and error.

Q3) Has anyone ever discovered any type of relationship between bib and lure size, they are willing to share. For example the minnow baits I am attempting will be similar in shape to Jakes, Grandmas, Shallowraiders etc. However my bait width/thickness will vary from these, especially until I figure out the additinal thickness I add from the clear coat and paints. I intend to use similar weighting locations as the named baits do, I found the Grandma templates online, and I will adjust the bib size according to the lure width (potentially add more width on shallow divers and more width and possibly length on the deeper divers). I plan to use linear extrapolation to come up with the starting bib sizes.  

Any insight would be greatly appreciated.  I will post any findings I make as I embark on this adventure.

Thanks

Mark

 

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I believe, from reading TU posts, that Etex is thinner than epoxy. I doubt that two coats would give a wall thickness of greater than 1mm.

Surface area is a difficult parameter to measure on a lure, so knowing the top coat thickness does not really help you.

I suggest that for the first few lures, that you accurately weigh before and after each coat to get an idea of the weight. Keep in mind that the density of the top coat for epoxies is around 1.2g/cm3. This means that the weight added to the lure is only 20% of the weight of the top coat applied.

Dave

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Someone posted the 'confused' smiley against my post. I just wish I knew what part of my reply was confusing. I am infamous for my bad explanations and over complicating things, and I do try to keep this fact in mind when I give technical replies.

My guess is that the confusion is the 'density of epoxy' comment, 'the weight added to the lure is only 20% of the weight of the top coat applied'. Let me try and qualify this statement without going into Archimede's principles.

People often think that if they add say 5 grams of epoxy to a lure that they are adding 5 grams of weight to the lure, and so 5 grams less ballast would be required.

Imagine if the epoxy density was 1g/cm3, the same density of water, in other words, the epoxy would be neutral buoyancy. No matter how many coats of epoxy that you added to the lure, no ballast effect would be added to the lure. A suspending lure would still suspend.

Now, increase the epoxy density to 1.2g/cm3 (20% increase). That extra 20% in density is heavier than water. 20% of 5 grams is 1 gram, 5 grams of epoxy adds 1 gram of ballast.

I think my explanation may have failed again. Perhaps someone out there who understands what I am trying to say, could step in and explain more clearly, it would be of great help to me and all the 'confused' out there :)

Dave

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Hey Dave, although originally I was a little confused myself once I though about it in terms of buoyancy I figured out what you meant. In my view your expaination is very good. I never thought of the added volume perspective. A simple way to look at it is also you are not just adding weight but also volume. 

Thanks for the advice it is greatly appreciated. 

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MarkR - very good (without trying to sound patronizing), you are right on the button. This is were the Archimedes principles comes in to play.

An accurate gram scale, beaker of water, a pair of long nose pliers and a simple calculator, and you can experiment and prove the above ideas very easily and simply, and learn a lot more about your lure at the same time.

The clue is in the density units: grams per centimeter cubed; weight divided by volume. But there I go, getting all technical again :)

Dave

Edited by Vodkaman
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5 hours ago, Vodkaman said:

Someone posted the 'confused' smiley against my post. I just wish I knew what part of my reply was confusing. I am infamous for my bad explanations and over complicating things, and I do try to keep this fact in mind when I give technical replies.

My guess is that the confusion is the 'density of epoxy' comment, 'the weight added to the lure is only 20% of the weight of the top coat applied'. Let me try and qualify this statement without going into Archimede's principles.

People often think that if they add say 5 grams of epoxy to a lure that they are adding 5 grams of weight to the lure, and so 5 grams less ballast would be required.

Imagine if the epoxy density was 1g/cm3, the same density of water, in other words, the epoxy would be neutral buoyancy. No matter how many coats of epoxy that you added to the lure, no ballast effect would be added to the lure. A suspending lure would still suspend.

Now, increase the epoxy density to 1.2g/cm3 (20% increase). That extra 20% in density is heavier than water. 20% of 5 grams is 1 gram, 5 grams of epoxy adds 1 gram of ballast.

I think my explanation may have failed again. Perhaps someone out there who understands what I am trying to say, could step in and explain more clearly, it would be of great help to me and all the 'confused' out there :)

Dave

Dave,

It was me (surprise, surprise), and this made everything clear.  Thanks.

Mark

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Mark - Glad you did mate, because I feel sure that you were not the only one. I had to think hard before I got my head around this stuff when I started my research on this subject.

Dave

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Dave I think you just solved a problem of mine I was having some time ago! :D for some reason I never considered density of epoxy in my equations. :lolhuh:As far as epoxy thickness and weight, on big baits it is still important, however starting with variables such as bill size and placement along with ballast weight and location will affect action more than topcoat. Topcoat should be last, so you should have more room to adjust it accordingly. There is lots of great stuff in the search function regarding size and bill shape. Generally larger the bait, larger the bill. Plus variables like depth goal  and placement. 

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Jonister - good comments.

Once the bait is moving, the topcoat has very little effect on a lipped lure, the dynamic effects of the water are so overpowering. Whether you design the lure as a 'sinker' or a 'floater', the lure is going to swim at a depth defined by the lip, eye position and the body shape.

Many TU members, some of which I have enormous respect for, will disagree with me on this point, but the parameters that I mentioned above determine the depth that the lure swims at. Line thickness also plays a crucial part.

Ballast distribution has a significant effect on the 'action', but because the epoxy is evenly distributed, action is hardly affected by the topcoat.

Knowledge of the density of the topcoat and the effect on the final lure density only matters if you are striving for a neutral density lure, in other words a 'suspending' lure, which I presumed that was the case in this discussion. Perhaps I should have asked the reason for the question in the first place :)

Dave

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You determine the thickness of a coat of ETEX epoxy by the time you wait after mixing it before you apply it.  Some wait as long as 15 minutes.  Fatfingers posted a member submitted tutorial on how he applied ETEX several years ago.  He obtains thick beautiful topcoats on musky lures.  His tutorial is titled Trying To Achieve a Perfect Finish.  Check it out.

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Thanks Dave and Bob. There are two cases I am looking at. One is for crankbaits, these will be floaters and in this case it was moreso the thickness I was thinking about. I was going to try to estimate what bill size I wanted by estimating the final thickness of the lure. I also am aiming for approx 20% of the bait above the waterline and was just trying to account for the epoxy. I also thought the epoxy would be thicker 3+ mm which I would think has more effect on teh lure. I think this is probably getting ahead of where I should be since I have yet to turn out a hardbait. I will also be attempting dive/rise jerkbaits and will aim for neutral buoyancy in those, or close to it so the weight would become more of an issue in this case. I am not specifically aiming for any "set" thickness for the epoxy, but based on bob's comment I better look into the tutorial.   

 

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MarkR - Planning ahead on a project, understanding your targets is a very good way to go about things, nothing wrong with this plan regardless of build experience.

I fail to see how knowing the top coat thickness is going to help you. If you really want such information, I suggest mix a little epoxy, paint several patches on say a tile surface or glass. Once cured, you can peel off and use a micrometer or vernier to determine the average thickness. Clamp ten patches together, measure and divide by ten for an accurate number.

But knowledge of the thickness is only of any use if you know the surface area of the body, such information cannot be calculated nor measured.

However, should you go the volume/weight route, both these parameters can be measured with great accuracy, to such an extent that you can create a suspender or a slow sinker, a 20% floater without ever doing a float test.

You need to think this through. Perhaps build a simple lure to test out whether what you are planning actually works. This is the power of prototyping, an opportunity to learn a great deal of the craft without the expenditure of many hours spent cutting the perfect body shape and creating a Rembrandt of a paint job, mistakes that first time builders often make.

Don't take this as criticism, you obviously have an idea. If successful, I am ready to learn, if not so successful, I am ready to help as are the other participants in this thread I suspect.

Dave

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Dave honestly it was something that I thought would matter more than it seems too. At least on cranks it doesn't seem to matter as much. For my jerkbaits I plan to make them with the ability to add/remove weights. I am going to glue rivet nuts into the bottom of the lures and make my own screw weights. This will take care of the issues with making neutrally buoyant jerkbaits as well, I will make them at approx 60% of neutrally buoyant weight (estimate off the top of my head I will examine this in a dunk test) but the aim is internal weighting for a quick to slow riser, and I will have the ability to add weights to get them closer to neutrally buoyant. Again, this is an idea at this time but I think it should be doable.

Your original comment on the 20% addition of weight, due to the volume increase, is what really made things easier and actually answered my question indirectly, made me think of teh answer. I never thought about the volume increase but you saved me many of head scratching days. As a starting point I was going to try and determine the final width of my lure, estimate based on epoxy thickness, and calculate the bill width, length and tie point location I would use accordingly to the dimensions of the lure. i.e I will dimension bills as a function of lure width and length, based on whether it will be a deep or shallow diver and use data from commercial type baits as starting points. For example Jakes, Grandmas, Shallow Raiders and others all have differnt lips and actions but are all minnow baits. So I will measure these lure dimensions and bill sizes/angles and take them into account when I develop the lips for my lure sizes. I figure this is as good of a starting point as there is, short of copying a commercial lure exactly which I prefer not want to do. 

Once my shop is finally set up at home, hopefully shortly in the new year I will get into making these. I will make sure I add any findings, good or bad in here to help others and pics as we progress.

Happy New Year to all

 

 

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You seem to have everything under control. I like your prototype plan with the adjustable ballast.

Do not make lip size a function of the ballast. The lip is the 'engine' that gives the lure its action. Once you define the required action by experimenting with lip size parameters, you can then go back and tailor the ballast to suit.

You are on the right track, good luck. Don't forget detailed feedback of your progress when you get started. Let people learn from your experiences, either in this post or a new post.

Dave

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A easy adjustable balast I learned and used just yesterday is lead solder wire. Especially on your first few baits, get it initially where you want it and then cater to water temp, line material, hook weight, distribution, etc with the use of lead solder around the hook shanks. A smaller diameter solder shouldn't affect hook ups too bad. I just used this on a floater jerkbait to make it slow sink in cold water. Another plus is its cheaper than suspend dots. So many possibilities! 

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