Good Morning All,
I have just finished my first crosswrap and am thinking ahead to how I am going to apply epoxy finish to the wrap. It looks to me that it is going to be heck on wheels trying to get it level. It is an open crosswrap and I have used regular and metallic thread, so are there any tips on how to get the finish to come out level?

Thanks,
Bill

Most don't get it level, because the wrap itself isn't level. The finish will follow the contours of your wrap. It will look fine.

Now some do prefer to have it completely level. They keep applying successive coats until they have sufficient thickness to allow them to then sand the surface flat (you do not want to sand into your thread, thus you need pretty good finish depth here). Once the surface is perfectly level, you apply one last application of finish to re-gloss everything. If you do this, block sand it - you can't sand anything flat with your fingers behind the sandpaper. You must put the sandpaper on a wood block.

........

I do what Tom says in the second paragraph, pretty much exactly as he put it. I used 220 grit with no problems with teh sanding marks showing up after the last coat of epoxy is applied. I do not recommend this unless you test it yourself - I've used 150 & 180 grit followed by 220 with no problems - be VERY careful if you do this. I do not find it neccesary unless you butcher teh finish pretty bad in one area (or your motor stops before the epoxy is set, lol)

I wipe with denatured & Iso 91%, let it dry, and apply finish. I'm not saying this is the right thing to do, etc, etc - it's what I do and I get decent results on my wrap finish.

The only thing I would change is the part about wiping with alcohol. This can lead to problems. What I tell people to do, is sand on through about 320 or even 400 and then dust off the surface with a clean brush. No solvents. Then apply the final finish coat.

It's a bit of work, but if this is what you're after, this is one pretty decent way to achieve it.

...............

"decent results". Remember that post about epoxy hating my wraps & how I get awesome results most of teh time but not every time. I really think the solvents are part of if not all the problem. I'll give that a shot, it's an excuse to buy a new brush...maybe I can use my beard? lol.

I've been wiping everything with alcohol between coats and I have yet to have a problem. Is this because of the type of alcohol? I only use Technical grade isopropyl alcohol that comes from a paint store. I'll also lightly pass the heat gun over the area I wiped to ensure it has totally evaporated before I apply the finish.

Here's the problem - there things other than solvents in these solvents. And, you tend to put any dust or debris into solution and then end up spreading it around all over the area you're planning on re-coating.

The general rule for the application of adhesive, paint, epoxy finish, etc., is this: Clean, scour/de-gloss and then apply adhesive or coating.

Wiping with a solvent should never be the last step before applying your adhesive or coating. On something like a sanded surface, you shouldn't be dealing with greases or oils, so no solvent should be needed. Just a dusting with a clean brush.

............

I'm very happy with the results i've gotten so far, so I guess I'll keep using alcohol. The store-bought (drug store) type can contain as much as 30% water, and I really think that can be a problem. Billy, I think your 91% might be a problem, not the fact that it's Alcohol. The type I use is 99.9% Isopropyl.

Bruce - if you watched how little care I take when I'm finishing, sanding, etc - you'd see that is the problem, lol. I never wash my hands, I touch everything, I wipe with solvent, I use dirty sandpaper. I still get decent results, but from time to time strange things happen which I cannot explain - I'll continue to figure it out, and maybe take a little more precaution when finishing.

Billy, If some of the Pro's saw how much air I introduce into my Flex Coat they would have a heart attack.......I measure the finish into two plastic bathroom size (3 oz.) cups placed side by side (very technical) mix the crap out of it, dump it onto my trusty aluminum pie tin, let it spread out a bit, then laze it with my heat gun to burst as many bubbles as I can. I then brush it on whatever isn't currently covered on the rod, laze it two or three more times with my trusty heat gun (usually over a twenty minute period), and let 'er spin while I'm off to bed. The next morning I wake-up to very nice results.....which I contribute totally to the Flex Coat engineering, not myself. I am a little anal about cleaning the surfaces before I apply anything though.

Sorry, double posted.



Edited 1 time(s). Last edit at 03/03/2006 12:48PM by Bruce Wetzel.

After I sand, I try to brush the dust off, but can never seem to get it all off, so I end up wiping down with denatured alcohol. Never had any problems.... yet. Guess I should just spend more time brushing the dust off.

Sean Endres
North East Rod Builders
New London, CT

Billy, if you go to using your beard, wash it first. Those Gummy Bear residues cause fisheyes for sure!

Putter
Williston, ND

If a stiff brush dont remove the dust a shot with compressed air (low pressure so you dont raise dust from everything else).If you dont have a compressor use the canned air used for cleaning computors and keyboards.

Freddwhy (Rapt-Ryte)

I use edge of an old credit card after brushing on the epoxy. Credit card rides the surface of the wrap leaving the voids filled in between as the rod spins. Extra epoxy wipes off onto card and then into a rag. Second coat results are pretty darn close to level and any sanding needed is very minmal.

I think the only problem with the "canned" air is the moisture that somtimes is expeled from the cans . I do use air from a compressor to "clean" the wraps (guide) before epoxy . Drain the separator first . John NERB

Got Fish ?

John Dow points out that: "I think the only problem with the "canned" air [used for cleaning computers and keyboards] is the moisture that sometimes is expelled from the cans."

Moisture may present a problem with spraying compressed air cleaner from a pressurized aerosol-type spray canister. ... HOWEVER, the moisture does NOT come from INSIDE the canister. (As a part of the quality control during manufacturing, they chemically DRY the air before they seal it inside the canister.)

Instead, what happens is the EXPANDING GAS (in this case, AIR) cools so rapidly and extensively that it COOLS down the rod blank, and causes the ambient humidity in the room air to CONDENSE on the sections of the rod blank where you just sprayed it. … And at the end of the little red straw thru which the air is blown. It’s the PRESSURE DROP that causes the rapid TEMPERATURE DROP. If you continuously spray the dust cleaner canister into the air for about 10 seconds, the canister itself will get so cold that condensate will form on the outside of the canister – thus proving that it is the water vapor already present in the room air that is the source of this water-condensate. It is not the air inside the canister.

That's THERMODYNAMICS in action, fellas - I'll spare you the lecture, ...!!!

But I will refer to the two most common appliances that capitalize on this cooling effect of a rapidly expanding gas – the Air Conditioner and the Refrigerator. The Compressor blows refrigerant vapor thru the Condenser, and the gas dramatically forms a liquid, because of the large PRESSURE & TEMPERATURE drop that occurs across the inside of the Condenser (which is the Heat REJECTOR grid in the back of the Refrigerator. The Liquid Receiver in automotive A/C is a separate downstream device between the Condenser and the J-T Expansion Valve.).

Typical mechanic shop air compressors simply use direct surrounding air intake, without an intake dryer. So, condensate will form from the expelled air, because water vapor is present on the low-pressure intake side of the compressor. And when the high-pressure air (500 PSI ?) passes thru the low-pressure regulator (30 PSI), the rapid cooling of the air-water vapor forms the water liquid. … You have probably seen this numerous times, when you fill your car tires with the proper air pressure. When you clear the air hose nozzle of debris with a long blast, a spray of water will soon pump out. ….

"OKAY, already, Cliff, - Let's get back to back to ROD-BUILDING !!! … "

Spraying the "dusting-cleaner" in shorter spurts of just ~ 1 second over a broader area should help prevent the surface from getting so cold that condensate forms on it. ... With THAT technique, a spray duster should work well. ... IMO, -Cliff Hall+++, Gainesville, FL-USA*****




Edited 1 time(s). Last edit at 03/04/2006 10:56AM by Cliff Hall.

LEarn something new every day. Today I learned about air cans & pressure and moisture. I want a Gold Star.

Ask Mike Joyce for a gold-frame turbo-wrapped wine glass.
Meantime, Billy, I'll give you 3 stars from me, * * *, -Cliff Hall+++

Now if we could just decide which cross-wrap spacing formula introduces the least amount of packing error at the tip end of a closed wrap, I could sleep well tonight. LOL!

Billy, is it just the first butt-end OD x 3.14 x (1 + % Taper) ? ...
That's the formula I keep getting when I use my Pecan Pi geometry methods.
But doesn't that spacing calculator result in the greatest distortion of the square?

I'm working on a formula to calculate rod blank mass distribution under a given line guide, but that will take at least a couple more Friday night beer sessions to verify that with my math-fishing buddy before I go completely dizzy. -Cliff+++