Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

sandblasting

Old 05-18-16, 05:43 PM
  #1  
DemonToes
Your life's just a spoke
Thread Starter
 
DemonToes's Avatar
 
Join Date: Jan 2016
Location: Buzzardville, AZ
Posts: 11

Bikes: Prestige(RIP), Peugeot

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
sandblasting

I want to give my ride a new look and figured off the bat it would be a piece of cake. Wondering if I can treat it like an auto job, grinder or sander for paint removal, rust resistant primer, and some classy enamel for the finish. What other considerations should I factor in here? Thanks!
DemonToes is offline  
Old 05-18-16, 06:07 PM
  #2  
andr0id
Senior Member
 
andr0id's Avatar
 
Join Date: Feb 2009
Posts: 2,526
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 1420 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
What's it made out of?
andr0id is offline  
Old 05-18-16, 07:15 PM
  #3  
HillRider 
Senior Member
 
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 31,489

Bikes: '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!

Mentioned: 32 Post(s)
Tagged: 0 Thread(s)
Quoted: 1141 Post(s)
Likes: 0
Liked 20 Times in 19 Posts
A bike is not the same as a car. Good bike frames are usually very thin metal. Even good steel frames use very thing gauge tubing walls and aluminum frames are even more fragile. Sand blasting is likely to do serious or fatal damage to either material. Carbon is definitely an absolute no-no for blasting media of any type.

Ask a local frame builder how he prepare his frames for painting and follow his advice.
HillRider is offline  
Old 05-18-16, 08:25 PM
  #4  
clasher
Senior Member
 
clasher's Avatar
 
Join Date: May 2009
Location: Kitchener, ON
Posts: 2,394
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 153 Post(s)
Liked 1 Time in 1 Post
Soda blasting is a more gentle media to use but I don't know if it'll work in a regular sandblaster or not. Plastic beads might be an option instead of sand.
clasher is offline  
Old 05-18-16, 09:03 PM
  #5  
DrIsotope
Non omnino gravis
 
DrIsotope's Avatar
 
Join Date: Feb 2015
Location: SoCal, USA!
Posts: 6,727

Bikes: Nekobasu, Pandicorn

Mentioned: 99 Post(s)
Tagged: 0 Thread(s)
Quoted: 3579 Post(s)
Liked 152 Times in 114 Posts
Media/abrasive blasting is likely unnecessary. The factory finish came off my bike in less than 15 minutes using water-based stripper and some Scotch-Brite pads.
__________________
DrIsotope is online now  
Old 05-18-16, 09:18 PM
  #6  
GravelMN
Senior Member
 
GravelMN's Avatar
 
Join Date: May 2014
Location: Rural Minnesota
Posts: 1,604
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 73 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
You can use a media blaster on steel frames but you need to be careful. Keep the pressure down and don't get up close and personal. I've got a spot blaster that I use with regular silica but only after chemical and hand stripping. I use it to get the last bits of paint and rust out of the corners as well as to give a fine, even satin finish to the metal which is the perfect tooth for taking primer.
GravelMN is offline  
Old 05-18-16, 09:24 PM
  #7  
tgolden
Member
 
tgolden's Avatar
 
Join Date: Apr 2008
Posts: 32

Bikes: Cannondale M800, F6 & CAAD9-5

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Vapor blasting is superior for this type of work.
tgolden is offline  
Old 05-19-16, 07:34 AM
  #8  
Kopsis
Senior Member
 
Kopsis's Avatar
 
Join Date: Apr 2008
Location: St. Pete, Florida
Posts: 1,260
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 83 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by HillRider View Post
A bike is not the same as a car. Good bike frames are usually very thin metal.
Modern automotive body panels are 22 gauge (0.8 mm) mild steel. Double butted steel tubsets are usually between 0.6 and 0.4 in the thin areas, but use a much higher grade (stronger) steel. A little caution is advised, but it's not like the walls will collapse if you look at them funny. With less abrasive media and/or lower pressures, media blasting is a completely safe method of paint removal for steel bicycle frames - and probably much less risky than a grinder or coarse power sander. Powder coating almost always starts with media blasting the frame.

But my advice for people looking to re-paint a bike frame is always: "don't". It's a huge time sink and it's really hard to get a good looking result that lasts. The two most effective techniques are catalyzed urethane automotive paint (expensive, needs high end equipment, requires lots of prep) and alkyd enamel brush painting (inexpensive, minimal equipment, requires lots of time for prep and application). Both use standard automotive prep techniques (etching primer followed by repeated application of conventional primer followed by wetsanding), but the tight angles and small diameter tubes make good spray application a real challenge. It can be done, but you'll be amazed how much time it takes to do it right compared to a (relatively) flat automotive body panel.

The best solution is powdercoating. It costs about the same as a urethane paint job but needs virtually no prep work and is significantly more durable than most other finishes.
Kopsis is offline  
Old 05-19-16, 09:22 AM
  #9  
hankaye
Senior Member
 
Join Date: Feb 2016
Location: 1/2 way between Hatch and T or C, N.M.
Posts: 240

Bikes: '95 Specilized StumpjumperFS

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 81 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Howdy All;

We used to use glass beads for "Blasting" aircraft skin (0.032"), when I was doing aircraft corrosion control.
But that was only as a last resort. We always used the mildest method possible. Generally an organic
stripper that was "killed" with water. Brass brushes for getting the bits out of wielding or other awkard
cracks and crevasses.

hank
hankaye is offline  
Old 05-19-16, 09:56 AM
  #10  
squirtdad
Senior Member
 
squirtdad's Avatar
 
Join Date: Jul 2006
Location: San Jose (Willow Glen) Ca
Posts: 6,126

Bikes: 90/91 De Rosa, '84 Team Miyata, '82 nishiski,

Mentioned: 55 Post(s)
Tagged: 0 Thread(s)
Quoted: 806 Post(s)
Liked 36 Times in 28 Posts
for a steel bike: Chemical remover. for a good paint job you need to get all the paint off no grinders, etc

Rattlecan jobs can come out very nicely, but are in no way as durable as automotive paint

steps at a very high level for a steel frame

remove all paint

acid etch primer

sandable primer

sand smooth

multiple thin coats of color, pay careful attention to recoat time...... IMHO easier to plan for a day and recoat as soon as possible

multiple coats of clear
__________________
Looking for Team Miyata F&F 58cm
squirtdad is offline  
Old 05-19-16, 08:57 PM
  #11  
Ronsonic
Senior Member
 
Join Date: Dec 2005
Location: Sunny Tampa, Florida
Posts: 1,391
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 54 Post(s)
Liked 2 Times in 2 Posts
Yellow Pages, powder coating, call, visit, write check for $100, take shiny bike home.

I've been down the DIY road. It can be done, it can look great. But unless sanding is part of the hobby for you it is wasteful of time that could be better spent.
Ronsonic is offline  
Old 05-19-16, 09:08 PM
  #12  
3alarmer
******
 
3alarmer's Avatar
 
Join Date: Nov 2010
Location: The Big Tomato
Posts: 17,274

Bikes: old ones

Mentioned: 226 Post(s)
Tagged: 0 Thread(s)
Quoted: 14533 Post(s)
Liked 71 Times in 61 Posts
Originally Posted by Ronsonic View Post
Yellow Pages, powder coating, call, visit, write check for $100, take shiny bike home.

I've been down the DIY road. It can be done, it can look great. But unless sanding is part of the hobby for you it is wasteful of time that could be better spent.
...+1. Life is short, and the PC guys blast prep stuff all the time. If there's a downside, it's that they sometimes powdercoat stuff you don't wan them to, like threads and crown race seats.
3alarmer is offline  
Old 05-19-16, 10:42 PM
  #13  
Andrew R Stewart 
Senior Member
 
Andrew R Stewart's Avatar
 
Join Date: Feb 2012
Location: Rochester, NY
Posts: 11,653

Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Raleigh Pro, Trek Cycle Cross, Mongoose tomac ATB, GT Bravado ATB, JCP Folder

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1730 Post(s)
Likes: 0
Liked 45 Times in 32 Posts
I was taught that most read a bike by it's cover, the paint job. So if you want your bike to look good and be thought of as a good bike then get a good paint job.

So what's a good paint job? Maybe one with a luster and depth of tone. Decals are smooth and seem to float in the finish. Joinery is not muddled and the crisp raw features remain so. Of course better corrosion protection and surface chip resistance are important. Better powder jobs get a few of these aspects well but only great powder jobs get most well. Low cost powder jobs don't get even the chip resistance good. Andy.
Andrew R Stewart is online now  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
alfred mcdougal
Bicycle Mechanics
14
08-29-13 02:48 PM
stringbreaker
Classic & Vintage
2
05-21-09 11:44 PM
md250r
Road Cycling
10
12-09-08 12:11 AM
crgowo
Mountain Biking
7
05-10-05 03:22 PM
drjuice164
Bicycle Mechanics
3
06-24-04 10:28 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

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.