JB Weld and Powder Coat

[Rick Iverson]

Gents;

In the move of the shop down from Brainerd last September, one of my NEW front wings was dinged up. I drilled a hole in the leading edge, pulled out the dents and hammered them slightly below the surrounding skin level.

Now, I need to doll it up. RP told me JB Weld is sandable (and more durabable than the surrounding blah blah thickness of wing skin). But I would prefer to powder coating them after cleaning the dents up.

I have no clue regarding the thermal expansion coefficients of either the aluminum and the JB Weld, but has anyone tried it. We’re dealing with 400 degrees F here. Thoughts?

V/r

Iverson

[Peter Olivola]

While not an aerospace epoxy, JBWeld is reasonably high temperature resistant. More than temperature, what is the duration of heating it will be subjected to?

[phantomjock]

Rick -

I picked up some High Heat JB - good to 450 F:


They also make an Extreme good to 2400 as I recall.
Local auto parts store - on the rack, 6 bucks or so..

Cheers - Jim

[Westroc]

I used to be a ASQE quality manager before I sorta retired. Yes 400F is about what automotive parts plants uses. On a slowly moving continuous line with tons of metal on it. Beware IF it is a stagnant oven. Although the temp is the same it's not moving and may be more (to a degree) susceptible to cooking whatever glue was used for the inner stays lay-up. Maybe maybe not. If they know what they're doing they will have concerns on how to hold it because it uses a water rinse using jets (automotive) to get it clean enough.And it's got to "hang on". Size should be absolutely no issue, most ovens you can walk thru with both hands up. Good size. You really don't want to know the utility costs. No idea if there is anybody down there. This is the centre of the world up here and there are 3 of any size, so not exactly common.

[Rick Iverson]

Gents;

I found this.

My research reveals the filler should be thinned to eliminate any air bubbles, perhaps requiring a couple coats. I think the fella giving the demonstration gobbed the filler on waaay toooo thick.

I will try it, take photos of the process, and the final product after powder coating.

V/r

Iverson

[JerryH]

If there is any bonding used in the wing manufacturing process, do not try to power coat the wing. The glue could melt leaving your wing very weak. Been there.....done that.

Jerry Hodges
JDR Race cars

[phantomjock]

JerryH -

Quick question - was the wing cored with foam? Was that the problem with powder-coating--baking in the oven?

Thanks - Jim

[JerryH]

Foam cores could be a problem.....but I Was referring to alum skins bonded together and to ribs and spars. The temperature of powder coating destroy the glues.