Wen Mac boat engine clean-up

Hey man I am cleaning engines too , Mind if I send you about a 1/2 dozen since you do do nice work Looks good Bob Eric

Thanks guys, It's a labor of love.......

Spare for the boat, maybe. But I'm hoping that I can scratch build something for it that would work.

Bob

I have often wondered about this engine (extreme bottom of picture) that I bought awhile ago in a box of parts engines.



It does not have the spring starter of other Wen Macs but rather the same back plate/thrust washer of the boat engine. I think it's a boat or maybe a car engine minus the flywheel. But it has the 90 degree needle valve assembly of the early Wen Macs rather than the angled needle valve assemblies of the later types.

But look at the indentation under the needle valve on the boat. It does not match the angle needle valve but rather it comes straight out to accommodate the earlier straight needle.



Needle in a haystack so to speak...........

The lower engine in the picture looks to have the smaller diameter thread on the crank, making it an early Mk1. Maybe that's just my eyes playing up again.

Nope, Not your eyes Rod, they are different sizes so this mystery of this engine continues.

Ok, my head hurts.  I just got through reading a zillion websites regarding the differences between Butyrate and Nitrate dopes.  Most somewhat contradictory, "Nitrate shrinks/No it doesn't Butyrate does" etc.

http://yarchive.net/air/dope.html

But this Wen Mac debate is helped by Marks contribution.  So my "mystery" engine is a pre 1952 release with just Wen Mac cast into the left side of the crank case, smaller diameter threaded shaft, and the 90 degree needle valve assembly.

Got it, until tomorrow afternoon...........

here's one for you...Nitrate Not for finish, Butyrate is Best

A friend of mine recovers full size aircraft in his job. He confirmed to me that Nitrate goes on first as it shrinks, then Butyrate goes over the top to seal. It can't be done the other way. This guy's a pro so I trust his information.
Also, he mentioned that so many fabric covered aircraft were painted silver because the aluminium powder in the paint acted like a sun-screen, much the same as our sun-screen. Interesting!!

Bob what about dying the wen make boat accesories red. Ive heard of this but never done it maybe another member has some experience wether it works well craig

Dying plastic, I will have to look into that.

I used Aero gloss clear and sanding sealer (sealer on balsa surfaces, clear on silkspan) on my Nieuport. My initial concern, expressed here that it did not tighten up the span. Not to worry, after three coats it's tight as a drum, without any visual damage to structure. But, most of what I have read declares Aero Gloss as Butyrate, but some say it's nitrate.

More internet confusion......

Mark Boesen wrote:http://www3.towerhobbies.com/cgi-bin/WTI0001P?I=LXAU61

Midwest Aerogloss says its Butyrate. Wasn't Aerogloss at one time a Pactra product? I've never used Nitrate dope, but mainly as it was not available in the hobby stores. Clear Butyrate made silkspan and silk taught. I had no problems with getting drum like finishes on these materials. As to whether one is better than the other, I can't say.

Anyone have good results with water based varnish, such as MinWax Polycrillic for filling the weave?

When i was a kid i built a Sig Banshee and used Sig butyrate (probably on the heavy side, dope make a great filler) it was amazing how much it warped the balsa!

You're correct, Midwest Aerogloss was Pactra, owned by Testors, I don't know when it changed, last couple years.

Lol, I remember people saying it was just a lacquer, not dope as it dried too fast! Looking back i'm sure that wasn't true, it did dry awful fast and seemed to crack easy.

For projects around the house i love the new water based polys, clean-up is a snap and the stuff is just as good as anything I've used in the past.

Thanks for the clarification, Mark. Well, I guess you could say that dope is a type of lacquer, but suited for aircraft due to its light weight. If cracking was a problem one could add a plasticizer. However as a kid, I never knew any difference. Back in college in the 1970's, I air brushed a Guillow Fokker D-8 covered in orange Japanese tissue with thinned clear dope. It blushed. In Honolulu, humidity was always high being on an island surrounded by water. I sprayed another light coat, which seemed to clear it up a little.

Used to be that hobbyist items were so reasonably priced even though at full retail. Nowadays finishes have gone up considerably in cost, at least that is my perception.

I remember hearing people adding a drop or two of caster oil or banana oil(?) to dope to reduce cracking? I never did as I never had a problem with it but once or twice, both with Aerogloss.

Mark Boesen wrote:http://www3.towerhobbies.com/cgi-bin/WTI0001P?I=LXAU61

Yes, I had found that and bookmarked it.

Recommends applying @ 70 - 80 degrees, I would have to wait six months.... I put one of the clear coats on at about 45 degrees, a warm day here in December, seemed to do ok. Also recommends 50/50 thin for air brush. I did about 1/3 thin for just plain brushing.

I guess I'm just going to camo it like the other one. I had bought the proper colors for it, used dope, and I don't know if the seller had thinned it or not. Still, I'm waiting for a warmer day, 25 here now. Inside painting this stuff gives me a headache.......