Go Back  Bike Forums > Bike Forums > Classic & Vintage
Reload this Page >

Powder coat dilemma

Classic & Vintage This forum is to discuss the many aspects of classic and vintage bicycles, including musclebikes, lightweights, middleweights, hi-wheelers, bone-shakers, safety bikes and much more.

Powder coat dilemma

Old 12-10-13, 05:41 PM
Mr. Anachronism
Hudson308's Avatar
Join Date: Jan 2013
Location: Somewhere west of Tobie's
Posts: 2,089

Bikes: fillet-brazed Chicago Schwinns, and some other stuff

Mentioned: 29 Post(s)
Tagged: 0 Thread(s)
Quoted: 524 Post(s)
Liked 255 Times in 164 Posts
Originally Posted by repechage
A tubular structure with possibly ornate reinforcements and their sharp edges and the possible multitude of braze ons that have often plenty of sharp edges and small cavities, all surfaces not easy to apply a nice uniform thickness of powder to be melted into a film. Also, consider what this fluid does in its semi molten state, it pulls away from sharp edges reducing the final film thickness there. Physics cannot be avoided. Experienced applicators of powder coat materials can make up for some of this deficit by adding material at problematic regions, a second layer will help even more.
Note I stated my experience was with single stage applications.
What I have found is that upon chemical stripping of all the single stage powder coat jobs on bikes I have had done or purchased over the years there is plenty of corrosion propagating from this thin film areas that was NOT visible from the outside looking in.
On a lugless bike with carefully radiuses edges and few if any braze ons one will have a better outcome.
A two stage application will by definition have a better chance of corrosion protection due to the additional film thickness.
With either approach, powder coat will obscure detail such as serial numbers and engraving, lug windows more, and more often than a wet paint job.
Certainly the nicest coverage on the three frames I've had done so far is the fillet-brazed one.

Originally Posted by 16Victor
Guilty as charged.
Might have been corrupted some by a favorite author... a dude named Rob Bell.
"My only true wisdom is in knowing I have none" -Socrates
Hudson308 is offline  
Old 12-10-13, 06:00 PM
Senior Member
etherhuffer's Avatar
Join Date: Aug 2007
Location: West Seattle
Posts: 1,359

Bikes: Surly Long Haul Trucker,81 Fuji Gran Tour SE, 83 Fuji S12S LTD, Voyageur 11.8 chrome, Raleigh R300 Touring, Voyageur 11.8

Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 263 Post(s)
Liked 433 Times in 197 Posts
Here is a Wikipedia quote

[h=2]Types of powder coatings[edit][/h]There are two main categories of powder coatings: thermosets and thermoplastics. The thermosetting variety incorporates a cross-linker into the formulation. When the powder is baked, it reacts with other chemical groups in the powder to polymerize, improving the performance properties. The thermoplastic variety does not undergo any additional actions during the baking process, but rather only flows out into the final coating.
The most common polymers used are polyester, polyurethane, polyester-epoxy (known as hybrid), straight epoxy (fusion bonded epoxy) and acrylics.
etherhuffer is offline  
Old 12-10-13, 07:52 PM
Senior Member
Join Date: Nov 2005
Posts: 5,770

Bikes: Cinelli, Paramount, Raleigh, Carlton, Zeus, Gemniani, Frejus, Legnano, Pinarello, Falcon

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Likes: 0
Liked 5 Times in 5 Posts
Originally Posted by howeeee
I prefer paint over power coat
Don't we all, but you're talking REAL money for paint these days. I've had 3 frames powdercoated for $130. each and I've been really pleased (they do a lot of brand new frames too). Now if I could just get my other 30 frames over there...
dbakl is offline  
Old 12-10-13, 08:00 PM
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 43,599

Bikes: 8

Mentioned: 197 Post(s)
Tagged: 0 Thread(s)
Quoted: 7607 Post(s)
Liked 1,349 Times in 856 Posts
Only in the WTC on 9-11-01, does steel melt at such a low temperature ..

BTW a Pro quality Imron catalyzed paint job aint cheap either , but it lasts .
fietsbob is offline  
Old 12-11-13, 12:04 AM
Senior Member
etherhuffer's Avatar
Join Date: Aug 2007
Location: West Seattle
Posts: 1,359

Bikes: Surly Long Haul Trucker,81 Fuji Gran Tour SE, 83 Fuji S12S LTD, Voyageur 11.8 chrome, Raleigh R300 Touring, Voyageur 11.8

Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 263 Post(s)
Liked 433 Times in 197 Posts
Originally Posted by fietsbob
Only in the WTC on 9-11-01, does steel melt at such a low temperature ..

BTW a Pro quality Imron catalyzed paint job aint cheap either , but it lasts .
Imron: hot rodders made it famous. No chipping!
etherhuffer is offline  
Old 12-11-13, 06:58 AM
Senior Member
SJX426's Avatar
Join Date: May 2008
Location: Fredericksburg, Va
Posts: 9,363

Bikes: '73 Bottecchia Giro d'Italia, '83 Colnago Superissimo, '84 Trek 610, '84 Trek 760, '88 Pinarello Veneto, '88 De Rosa Pro, '89 Pinarello Montello, '94 Burley Duet, 97 Specialized RockHopper, 2010 Langster, Tern Link D8

Mentioned: 68 Post(s)
Tagged: 0 Thread(s)
Quoted: 1525 Post(s)
Liked 2,024 Times in 1,001 Posts
Back in the day I was doing desing work, we powder coated our front and rear castings of aluminum because the instrumentation was a mobil design. Testing of impact, abrasion etc of powder coat showed a 40x resistance to damage comparted to the best wet paint application like Imron. PC was fairly new back then and was only avalialbe with a process of 400 degree ovens. Today you can do it in 250 degree ovens and in your own oven. That was over 30 years ago and I have not kept up with the developments of PC since. I assume it is still used for the same reasons, plus the ease of application and compliance to environmental regulations along with cost effectiveness. Back then there were issues of masking too which don't apply today.
SJX426 is offline  
Old 12-11-13, 12:22 PM
Senior Member
Join Date: Dec 2005
Posts: 7,859
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 1 Time in 1 Post
What the OP can do is try to find somebody doing Electrostatic Painting, that paint is not baked. My old miyata pro had that finish, the nice about it is that is not baked, second the finish gets almost as hard as appliances finishes and pretty much you can paint over chrome plating, sure you guys have seen several japanese frames that are chromed under it, that this has to be Electrostatic Painting.

The other advantage is that the layer of paint is quite thin as regular wet paint, so any frame embedded in the frame or fork will be nicely kept.

For the record never seen anybody doing this for bikes so could be a challenge to find a guy doing it.
ultraman6970 is offline  
Old 12-12-13, 10:33 AM
kunsunoke's Avatar
Join Date: Mar 2013
Location: Fleetwood, PA, USA
Posts: 1,005

Bikes: '84 Colnago Super; '90 Bridgestone MB-1; '81 Trek 930; '01 Cinelli Supercorsa; '62 Ideor Asso; '87 Tommasini Super Prestige; '13 Lynskey R2300; '84 Serotta Nova Special; '94 Litespeed Catalyst; etc.

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 118 Post(s)
Liked 86 Times in 57 Posts
Imron is indeed great stuff, when properly catalyzed and when the surface is prepared properly beforehand. Such was not the case with my Trek 600, which had to be stripped and powder-coated thanks to an extensively chipped and scraped Imron paint job.

The prices for Imron paint jobs have everything to do with the labor-intensive nature of the preparation and paint process, and with the toxicity of the isocyanate cross-linkers used (requiring PPE for the paint shop workers). Preparation for powder coating is a lot less of an involved process - you need racks, an applicator gun, the powder itself and a suitable large oven & that's it. No solvent handling/recovery, no problems with overspray, few toxic effects (unless you breathe it in directly). The powder itself doesn't require clean-room conditions in order to adhere properly.

Steel didn't melt at WTC 1, WTC 2 or WTC7 for that matter. It didn't have to melt. Because it softened instead, losing over fifty per cent of its original strength in the process. Thermal expansion was also a factor, resulting in the sagging of the affected floors (ex. WTC 1&2) and the loss of the anchorage for the horizontal column support members (particularly in the case of WTC7). Fire protection coatings weren't up to modern standards, which did not help - nor did the presence of copious amounts of papers, files, furniture, rugs, and other combustibles (particularly in WTC7, which burned viciously for hours). It also must be remembered that the jet liners punched through a number of support members in slicing through towers 1 and 2, thereby placing the towers in jeopardy even without the fires.

Last edited by kunsunoke; 12-12-13 at 10:38 AM.
kunsunoke is offline  
Old 12-12-13, 10:55 PM
Senior Member
Join Date: Jun 2006
Posts: 19,243
Mentioned: 125 Post(s)
Tagged: 0 Thread(s)
Quoted: 3053 Post(s)
Liked 2,224 Times in 1,602 Posts
Originally Posted by pfaustus
I didn't realize that power coating was baked at 400 degrees. That is sufficient to temper hardened steel. That leaves as questions, however, whether the frame is hardened steel or whether it has already been tempered.
Reynolds 531 and Columbus of the period were delivered in a normalized state. 753 was heat treated.
The suggested processes for 531 at least does not require post joining heat treatment. It was used elsewhere and did have some other processing notes for the specific use/application. Penton used 531 for some motorcycle frames, and it was also used in some airframe sub assemblies such as engine brackets. You can even stick weld the stuff.

Not all powdercoat requires 400 F to transform.
repechage is offline  
Old 12-12-13, 11:23 PM
The Brutally Handsome
Sizzle-Chest's Avatar
Join Date: Jun 2007
Location: Siberia
Posts: 508
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
I've only had one frame powder coated but I was not pleased with the results. It came out with a wavy texture that looked terrible in the light. And as other have mentioned, it seemed really thick, covering some of the frame's finer details. I was more happy with the rusty scratches it had before!
Sizzle-Chest is offline  
Old 12-13-13, 12:49 AM
Other Worldly Member
Jseis's Avatar
Join Date: May 2012
Location: The old Northwest Coast.
Posts: 1,540

Bikes: 1973 Motobecane Grand Jubilee, 1981 Centurion Super LeMans, 2010 Gary Fisher Wahoo, 2003 Colnago Dream Lux, 2014 Giant Defy 1, 2015 Framed Bikes Minnesota 3.0, several older family Treks

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 194 Post(s)
Liked 135 Times in 52 Posts
Yum, more zombie frames. I'd walk back to that LBS with a D cell and a couple of leads and restart that frame "Clear!".
Make ******* Grate Cheese Again
Jseis is offline  
Old 12-13-13, 01:01 AM
Senior Member
Join Date: Oct 2013
Posts: 87
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Must be a big oven to put a ship in to cure the powdercoat.
MacNasty is offline  
Related Topics
Thread Starter
Last Post
General Cycling Discussion
11-16-17 04:48 PM
Bicycle Mechanics
08-16-13 07:50 AM
Mountain Biking
03-04-13 10:41 AM
05-31-11 08:03 PM
General Cycling Discussion
02-06-11 05:35 PM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell or Share My Personal Information -

Copyright © 2023 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.