BillS

CA and heat

I am considering using CA or maybe epoxy to patch a hairline crack in an engine. The hairline is at the carburetor barrel mounting.

Has anyone had experience with CA and hairline cracks in locations that get hot? What were the results? Ay advice?

bigchap

i think it is a huge risk using ca,i would maybe think about using devcon if it was a real expensive engine otherwise i would bin it,you really cannot afford the risk of a lean run.

Scar

My Feedback: (3)

A hairline crack.... as in, the carburetor hit something and broke out the engine? Or as in, there's a gap at the O-ring mounting?

If there's been a mechanical leverage on that carb, to open a crack in the block, I think you'll have some deformation inside. Some engines need a tight clearance for the crankshaft to spin in, under the carb.

If it's just a casting flaw or an undersize O-ring, all you need is some Hi-Temp Silicone Sealer. If it's a deformed crankcase, you might want to run it on a test stand after you fix it, for a few tanks, to make sure there's no interference. Or, to make the flaw exhibit itself.

Good luck,
Dave Olson

BillS

Good suggestion. Silicone had not been considered and it is probably a better choice. Based on the location the mechanical strength will probably be ok except for (maybe) vibration. Sometime in the life of the engine there has been a mechanical leverage as in crash.

Thanks for the ideas.

Knighthawk2100

Go to home depot and get some liquid steel

Dragonjohn

My Feedback: (5)

I have (am using ) silicone on a S. tiger .45 with a similar results no problems I did run several tanks through it before I mounted it on the plane. I have used liquid steel as well (I think of it as hi-temp epoxy, with a metal filler) on a four-stroke as well. only on fractures and nicks though I would recommend drilling and tapping a screw or two on either side of the carb (like the O.S.'s or K & B's) to hold the carb inplace. If you have a pinch type bolt holding the carb down.

Complements on the knight with the one liner, reminded me of that particular .45, went inverted with a trainer and went up instead of down.. left about a 6-7 inch hole in the ground!

twostroke

My Feedback: (6)

Rough it up with sandpaper and put some JB Weld on it.....It will be as good as new!!!

MinnFlyer

My Feedback: (4)

Yup, JB Weld, or liquid steel has saved many an engine for me,

britbrat

Another vote for JB Weld -- it works very well -- even on holes in the crankcase.

jettstarblue

I have 3 engines that are held together with JB Weld... one is a 4 stroke (carb mount).
Nary a hiccup!

BillS

Just information. A web site was found that indicated JB weld is good up to 500 degrees F.

jettstarblue

They also make "High temp." JB Weld, tried it once, and hey, it didn't melt either!