High temp caulk??

[Davek0974]

Is there a sealant or caulk that will be powder-coatable??

I guess it needs to withstand 240c but would powder stick??

I have a line of outdoor parts that have a T joint and unless I fully fillet weld it, which is serious overkill, water will get in the joint and rust out quickly.

I thought a thin bead of sealant before coating might do the trick??

 

[steveo3002]

cant you run a neat bead of sealer around it once its coated?

 

[Kent]

here is my guess NOPE! Everything powder coated needs to conduct electric does it not?

 

[Davek0974]

Probably, not sure about neat though

It also adds a drying stage to the product, probably overnight.

Was looking for a pre-coat sealer, this seems to be the one...
http://ctaltd.co.uk/pre-powder-coat-seam-sealer-15000/

Hate to think of the cost and shelf-life though, will try to find out.

Edit
It's 19.50 / tube but only sold in 12's so thats out

 

[Davek0974]

here is my guess NOPE! Everything powder coated needs to conduct electric does it not?

Not necessarily it seems, I have seen the electrostaticmagic advert where they were coating wood and glass bottles!

 

[Wendelspanswick]

If you preheat stuff and then shoot the powder it will stick. It just needs to be able to withstand the 160 deg C plus curing temperature.

 

[Wendelspanswick]

http://www.screwfix.com/p/geocel-trade-mate-plumba-flue-silicone-black-310ml/66373

 

[Davek0974]

http://www.screwfix.com/p/geocel-trade-mate-plumba-flue-silicone-black-310ml/66373

Looks like its worth a test, I have read bad things about silicone and coatings but as its a small bead, might be ok.

 

[Kent]

If you preheat stuff and then shoot the powder it will stick. It just needs to be able to withstand the 160 deg C plus curing temperature.

Sticks like S*it is the best I have found in a flexible sealant on temperature resistance, without a tube I could say how hot but it certainly over 100

 

[steviec_lj]

Used to use SikaFlex at one place, on everything and anything the "preppers" wanted to.

Items were preheated, then coated after the SikaFlex had been applied. Will have a look which product it was, as I've probably still got some lurking around..

 

[daleyd]

Used to use a lot of Dow corning high temp silicone, red in colour. I think that was good for 300 degrees or so off the top of my head.

 

[the snooper]

Looks like its worth a test, I have read bad things about silicone and coatings but as its a small bead, might be ok.

paint and alike doesn't stick to silicone

 

[Kent]

Some of these new sealants you really can paint onto others well verge on blatant mis -description of goods

 

[chevy2]

Look into intumiscent mastic, comes in a silicone type tube,
we occaisionally use it a work to seal around fireproof vents.

 

[richie00boy]

Original JB Weld epoxy is supposed to be good to those kind of temperatures.

 

[SmartWerks]

Looks like its worth a test, I have read bad things about silicone and coatings but as its a small bead, might be ok.

Silicone and coatings don't mix.

The the op, what metal are we talking about. We have to overcome the same problem with steel wheels.

 

[Turbo]

How about exhaust sealant, you can get it in a mastic type tube. Novatio also do a high temp instant gasket rated to 300+ deg C, I used to use it on steam boilers.

 

[Davek0974]

The materials were plain mild steel.

I have redesigned the parts so that they only have two points of contact and both of those can be fully welded - its much better than it was before and no sealant needed.

I have made a note of the suggestions on here though - some good stuff.