Rescuing a Pace RC200 F4 Frame

[danson67]

Thankfully the Pace is 7005-T6 (or possibly 7020-T6, they just say 7000 series?), so only a light few hours at 180º to normalise things.
A new build 7005 frame would get 8-10hrs at 180º, in line with Columbus and Dedacciai guidelines, or (allegedly) leave at room temperature for a month to age before using.

6061-T6 repair is a bigger matter, as any extra heat cycles from welding or ageing can over-treat the existing T6 condition metal making it brittle.
The proper full quench and re-ageing (525ºC +/-15º then quench down to T0 condition in water, align within 8 hours, age at 165-195º for 3-12 hours back to T6.) is expensive and risky to alignment etc with a lightweight structure such as a bike frame.
There are loads of variables, and should really be done on test pieces etc first, which just isn't possible with repairs.

All the best,

 

[66 triumph daytona]

Would I be correct in assuming that 7005 that isnt T6 hardness needs no heat treatment post welding?

 

[danson67]

Re:

I would have thought sub-T6 temper would need a treatment to get the strength up post weld. 7020-T4 is down about 30% on proof stress and 15% tensile strength compared to 7020 at T6. So the whole frame would be closer matched to the weld material (at T0), but weaker and softer temper than if it was all aged up to T6.
Any pro metallurgists in the house, this is a bit above my pay grade :shock:

The advice seems to vary quite a lot and since 7005 is only widely available as bike tube, I usually go by the tube manufacturers' guidelines.

Columbus say that their tubing is 7005 supplied in T6 condition, but:
"The heat treatment is strictly recommended, (within?) 4/5 days after welding: artificial ageing 6h at 90° C, then 4h at 150° C."

Dedacciai only say 7XXX for their alloy, but you need to use their own supplied filler rod (5183 I think, as there's no green flare like 5356) and:
"Post welding treatment:120 c° +/- 5 c° 12 / 14 hrs"

Their top V-107 tubing is very different (7003-T6) requires some serious handling, with strict weld sequences and a full quench and age: Guide here.

The story goes that 7005-T6 was adopted by the Taiwanese bike industry as it could naturally age at room temperature during 6 week surface transit time to the US shipping ports. So maybe, if you can wait a few months before using, no heat treatment is OK. I should run some test pieces...

All the best,

 

[Ollie]

Woah ! Great rescue on the frame , turned out awesome .

 

[boxxer]

Dan

How much would it be to Powdercoat a SC Bullit Main Frame and Rear end along with a set of RS Boxxer lowers in one of the Candy transparent Red Powdercoats?

Current one is starting to come off both Frame and Forks and as I'll be using it for a while to come then its worth me getting it sorted....

 

[Papillon]

Re:

Hi Dan
Been trying to contact you via PM as every time I try it will not send have contacted site administrated so hope I can get you via PM when sorted
Frame looks wicked many thanks will chat when PM is working
Papillon

 

[danson67]

Re:

Hi Max,

Try a PM via danchambers67 at gmail dot com.
I'll get that OK.

All the best,

 

[danson67]

Re:

Boxxer:How much would it be to Powdercoat a SC Bullit Main Frame and Rear end along with a set of RS Boxxer lowers in one of the Candy transparent Red Powdercoats?

I didn't do the powdercoating myself, but it was done by a sub-contractor, Quality Plus in Sandy, Bedfordshire who I use for my other stuff (racing wheelchairs).

Candy finishes in powder are really difficult, as the finish is so dependant on the thickness of a coloured translucent top coat, which, unlike a wet paint, is not translucent when you apply it, so is very hard to judge. We prefer Tiger Dormant Red, where the red colour starts off being carried by a silver-based undercoat, giving a good even finish, then is top-coated with a clear coat which draws the colour out of the undercoat into the top coat to give the deep metallic 'candy' look, but far more reliably.

We buy in the powder ourselves, usually from Tiger UK (office.gb@tiger-coatings.com), Caswell coatings, or plenty on ebay etc). It can vary from £5/Kg for the basic colours, up to £50/Kg for fancier metallics etc. A kilo will cover 3-4 frames probably.

Quality Plus have a minimum charge of £55 + VAT. They don't do any grit blasting, just degreasing, so I usually have decent frames (especially any aluminium ones and my racing chair frames) soda blasted at Soda Blast East, in Rushden, Northants.,costing around £30. but can get any tougher beater frames grit blasted for £10-15 each.

All the best,

 

[Rampage]

Re:

Surprised you use Caswell, they are a nightmare to deal with!
Although they have changed the UK distributor recently, are they better now?

 

[danson67]

Surprised you use Caswell, they are a nightmare to deal with!

Were you sourcing stuff from his plating and anodising range?
I only used them for small one-off powder orders as TigerDrylac are really expensive for small orders. No problem if you can justify a 20Kg box, though.

John Payne, who was CaswellEurope, (it was a UK-based reseller arm of Caswell Plating in the US for anyone who doesn't know them) retired last year and sold it all to a company called ProTurf who sell small tractors and off-road utility quads out of Farnborough.
I've ordered a couple of batches of powder (day-glo in 1Lb tins) from them since and it all seems a whole lot better organised than when John ran it. He was keen, but a bit disorganised IMHO.

And of course there's always plenty of outlets on eBay...

All the best,