Preparing a new unpaintet frame for first time powdercoat - advice please

Hello people

So i bought this unfinished frame from a forum member, its supposedly Columbus SL tubing. It has never been painted and has been stored for some time.
It has very little surface rust and all the excess flux is till on it -it has not been filed or sanded down.

I would like any advice that you could give me regarding preparing this frame, before it goes out for powdercoating.

What should be done?
Should i get the seattube honed? - right now a 26.8mm seems to fit.
Should the frame be sanded to "near" mirror finish before its first time paint?

Any experienced advice is welcome, i'm prepared to put in a lot of hours to get this project as good as can get.

I've already begun filing the lugs a bit as you can see from the pictures.

Here's some images

Here's some links to the rest:
http://www.victorfacius.dk/img/columbussl/2.jpg
http://www.victorfacius.dk/img/columbussl/3.jpg
http://www.victorfacius.dk/img/columbussl/4.jpg
http://www.victorfacius.dk/img/columbussl/5.jpg
http://www.victorfacius.dk/img/columbussl/6.jpg
http://www.victorfacius.dk/img/columbussl/7.jpg

Hope theres anyone out there with experience in this area.

If you are taking it to Armourtex, as most of the forum seem to do, they will prep it for you. Here are some threads on them

http://www.lfgss.com/search.php?searchid=3907364

Powdercoat tends to show up any imperfections, rather than hide them so make sure everything is finished and filed up nicely. Apart from that a quick run over with some sandpaper to get off a bit of the rust and your set. The coaters will rub it down with thinners before applying the powdercoat.

^^?!?
powdercoat is the most forgiving paint finish out there.
It will cover just about anything.

Wet paint and stove enamel are the prep-heavy finishes.

I live in Denmark so im not taking it to Armourtex :) i'll use a local powdercoater.

Any advice on the seat tube? should i hone it up to 27.0?

Here's a picture down the seat tube, looks a bit dirty/rough ehh?

There's something odd about the seatstay, what's up with that?

It looks as the seat stay has not been brazed to the lug, it appears to be stuck with thick dried flux, also the rust marking on the frame will probably not sand out it would clean better with blasting and the inside of the seat tube looks as it needs reaming.

facius, take your frame to a local framebuilder and get it checked properly before you start painting it in flamboyant colour.

unless you do it in black, then you're fine

You need to get it an acid etch primer on there ASAP, straight after it is oxide blasted, so the paint will adhere. As previous posts, get a framebuilder to look at that seatstay.

defanatly ream the post, easily the roughest looking seat post tube I've seen.

Thanks for all your answers.

I took it to a professional frame builder to get a closer inspection.

The seatstay was a bit out off place, but is was welded well enough to hold.
As for the rest, he didn't have much good to say.

Here's what he pointed out:
*1. The tubes had not been properly cut to fit.

1. All the joints had been overheated.
   
2. Not welded very nicely.
   *
   Soo.. basically everything important was wrong.
   He predicted it would probably be very wobbly and feel like riding a chewing gum :(
   
   

As i was talking to this one guy/the owner, one of his employees came by and said:* "uhh damn, looks like some apprentice work"

Sooo... guess i've learned a lesson this time, be careful what you buy over the Internet. Even if its from the good folks at London FGSS.
*

Damn, sorry to hear that you got a dodgy frame, but glad that you found out now rather than later!

That sucks.

If I were you I'd build it up and see how badly it rides (more out of curiosity than anything else). If its ok then paint it. But probably best off as a pub bike if its as bad as that guy says.