A few possibly Dumb questions......

Is there a reason to start at the top of the header and go down? Starting at the top leaves the upper edge exposed, and in my tiny mind that seems like it would collect moisture/water easier, or does it not matter either way?

Brackets etc: ill be taking the pipes off to wrap them, should I leave the brackets mounted on the pipe and wrap around them, or remove and clamp the brackets over the wrap when reinstalling? Or is this an aesthetic choice only?

Apart from making the headers look a bit beefier, does doing a double layer of wrap add/detract from its functionality?

TIA!

8's

 

I am curious what help is offered as I am about to do this to one of my bikes.

 

I'd wrap around your brackets.

As far as top to bottom, I don't believe there is a particular reason other than to make sure both pipes are wrapped to the same point. If you come up a little short, it's easier to unwrap the bottom half and reduce your overlay than it is to unwrap and re-wrap the bent portion. Any moisture accumulated in your wrap will quickly evaporate in a cloud of steam. It's neat to see.

Fair warning: wrap retains water and holds it against your pipes. This will lead to rust issues that will likely go unnoticed.

 

Yeah ive heard this. Wanna wrap for the moment as the front heat shield is residing in a field in France somewhere and rear one is starting to rust through its brackets now. Will probably replace the pipes in the coming year anyhow, depending how long the pipes last while wrapped.

 

I've wrapped the headers on my turbocharged drag car a time or two, (keeps the heat in to spin up the turbo quickly) and I've had the best luck starting from the flange (head) end. I'll do one complete turn, then start down the tube overlapping half the width. Secure the end with a hose clamp. The flang end needs no clamp doing it this way and looks cleaner IMO.

I painted my header with several coats of high heat exhaust paint, and still got a bit of rust after three years. For something that gets wet frequently, like exposed exhaust, yeah it'll rust quicker.

The DEI brand made from what they call "Rock tex" is easier to wrap than less expensive fiberglass wraps. You'd has to to decide if the cost is a factor. Also, the fiberglass wrap stinks to high heaven when you first get the pipes hot.

 

I started from the rear and go forward. That way the overlap edge faces rearward so that it does not fray as much due to wind or other debris nicking at it. Not sure if that really matters though. Dont park it wet. Let it run a bit especially if you wash the bike.

 

Not sure if top down or vice versa matters, but what DonN said about the overlap makes sense. I have always started top down.
As for doubling up, not sure it will help that much more. Most wrap is meant for a single layer. There are lots of options out there and some are not worth the money (IMHO). The non colored are better, since you need to soak the wrap before putting it on (this will cause the color to wash out), in order to get a tight finish when dried. Once dry, DEI makes a high heat spray, that can be applied for the black look (be aware it will take about 20 minutes for this to quit smoking on initial start up). Most company's incorporate a black thread on both edges of the wrap to act as an overlap guide and ensure proper insulation. In my experience, for systems with tight bends on small diameter pipes (like motorcycles) the narrow width wrap works better and is easier to work with (the wide stuff tends to leave bulges & wrinkles).
I'm not exactly sure what you mean by "brackets" but if they can be removed take them off before wrapping; those that are permanent, wrap around; this has been my philosophy over my years.
I hope this has helped. Good luck.

 

It took about a year for mine to break all the way through. The metal gets weaker from the tape preventing the metal from cooling down at it's own pace. Only wrap pipes if you plan on getting new pipes in a year or two.