PaintSquare.com
      | Connect Follow us on Twitter Like us on Facebook
About | Subscribe | Advertise
  

 

Download our free e-book! Surface Preparation & Safety

Problem Solving Forum

| More

April 16 - April 22, 2012

How long can a blasted surface be left before priming under different temperatures/relative humidity environments?



More items for Surface Preparation


Selected Answers

From remko tas of Futuro SRL on April 17, 2012:
     As a curiosity; flash rust did not occur for 10 days in a dry climate at an altitude of 4000m (13,000ft) in Bolivia, hundreds of kilometers away from the sea influence and contaminating industry. We could still safely paint the interior of the tank in one shot, achieving a high efficiency.

From Lubomir Jancovic of MSPLUB Inc. on May 1, 2012:
You have to prime the blasted surface of steel in up to 8 hours. Otherwise,  blasting was for nothing. If humidity is more like 60%, you have to prime the surface in up to four hours.

From Charles Williams of kurbtblast on April 16, 2012:
     Depending on the situation and coating system, we do not leave surfaces uncoated for more than 24 hours. Some epoxies have a tolerance level for flash rust (bloom), but when a zinc primer is required, we will coat the same day. Not all situations require same day priming, but some do. Our max time for leaving anything uncoated is 24 hours on warm dry days.

From Lee Edelman of Independant on April 19, 2012:

Always attempt to prime the prepared surfaces prior to the specified surface prep degrading. Most specifications will address this. Humidity and dew point should be monitored throughout the process, so that  when humidity or dew points exceed specification, there should not be any painting activities.

If the surface prep has degraded, most specifications will require reblasting to the specified surface prep.

From richard d souza of stoncor middle east llc on April 16, 2012:
     It is not about how long but the highest criteria is the steel temperature shall always be at least 3 degrees C higher than calculated dew point temperature. This margin of saftey is sufficient for all type of coatings. The common scenario is that the contractor blasts all day long, then experiences problems with the compressor or other piece of equipment, and lets the newly blasted steel sit a long time before coating. But the standard requires that the surface to painted must meet the cleanliness criteria set by the client or consultant which supersedes every other judgment. In Jordan, for example, oxidation or orange rust may not occur for serveral hours or days, but in UAE, you can probably expect to see rust breakthrough in few hours depending on the time of the day or night. It is almost impossible to state the effect of time,   temperature and humidity  on the blasted surface. This  must be the sole responsibility of the inspector, who conducts on-site checks of the following: -Place of work -Air temp min/max -Relative humidity -Dew point temperature -Steel temperature -Necessary ventilation -Type of weather-sun, wind etc. -Wind directions. And this must be done a minimum of thrice per shift. The inspector should have the sole right to determine the time without deviating from the specification.

Please sign in to submit your answer this question    

Tagged categories: Abrasive blasting; Humidity and moisture; Substrates; Surface preparation


Current PSF Question | Submit a PSF Question | Full PSF Archive

Minerals Research & Recovery

HIGH PERFORMANCE ABRASIVES


“Made in the USA!”

Why recycle waste from other countries? Go FASTER, CLEANER, at 1/3 THE COST with MR&R “All-American” Sharpshot®HP!!

WATCH THE VIDEO


Atlantic Design, Inc.
CLICK HERE

to see what we did to this dust collector! ADI can increase the efficiency and life of your equipment! Any brand, for less than new! 866.Call.ADI


Axxiom Manufacturing
Revolutionary Units

By integrating Schmidt's Aftercoolers with our blast pots, these systems remove moisture from air and minimize equipment footprint on jobsite.
Call 1-800-231-2085


Advanced Recycling Systems
ADVANCED RECYCLING SYSTEMS (ARS)

Recycling Machines, Dust Collectors, Rapid Deployment units are time-tested and approved for the rugged industrial environment. Contact ARS today!
(330)536-8210


Abrasives Inc.
Check our Prices for Blast Abrasives

Faced with higher abrasive costs? We invite you to call & check our rates on Black Magic® coal slag and other quality blast materials. Abrasives Inc. 800-584-7524


Harsco
BLACK BEAUTY® App

Download the free app for BLACK BEAUTY® Abrasives. Explore all the features from the palm of your hand.
Toll Free: 1-888-733-3646


NLB Corporation
MiniARM automates surface prep

NLB’s Mini ARM lets an operator control high-pressure water jets remotely, with fast tool changes for different jobs. It maximizes protection and productivity.


Industrial Vacuum Equipment Corp.
Hurricane Vacuums
& Dust Collectors

Vacuum and dust collector hose, filters and related accessories.
IndustrialVacuum.com


Absolute Equipment/Grand Rental Station
Portable Power from Absolute Equipment

•Compressors
•Lighting Systems
•Generators
•Light Compaction
Sales • Rental • Service
Call 1-866-931-6655
Over a century of
providing excellence.


Novatek Corporation
Dustless Coatings Removal

Strip it, clean it, and profile it,
all dust free! High production
rates and Blast like finishes.
Comply with new lead
standards.

 
 
 
Technology Publishing

The Technology Publishing Network

The Journal of Protective Coatings & Linings (JPCL) PaintSquare
Durability + Design Paint BidTracker

 
EXPLORE:      JPCL   |   PaintSquare News   |   Interact   |   Buying Guides   |   Webinars   |   Resources   |   Classifieds
REGISTER AND SUBSCRIBE:      Free PaintSquare Registration   |   Subscribe to JPCL   |   Subscribe to PaintSquare News
MORE:      About PaintSquare.com   |   Privacy policy   |   Terms & conditions   |   Site Map   |   Search   |   Contact Us
 

© Copyright 2000-2015, Technology Publishing / PaintSquare, All rights reserved
2100 Wharton Street, Suite 310, Pittsburgh PA 15203-1951; Tel 1-412-431-8300; Fax 1-412-431-5428; E-mail webmaster@paintsquare.com