How to test for welding flaws with Sherwin NDT
If you're working on a welding project, and you need to check for flaws, or cracks, Sherwin non-destructive testing sprays are a quick, easy and reliable way to do it. We'll show you how...
What you'll need
1. Clean the surface
It’s really important to clean the surface BEFORE the penetrant is applied. This is to make sure grease and dirt are not filling or covering up any defects and preventing the penetrant from getting to them.
Just spray Sherwin DR-60 Cleaner
directly to the surface and wipe with a clean, dry cloth.
2. Apply the penetrant
Spray Sherwin DP-50 Penetrant
directly over the weld from approximately 30cm away.
Leave the penetrant to sit to allow it to penetrate into the cracks, minimum dwell time is 5 minutes, but leave it longer for improved accuracy, or in cold environments – if ambient temperature is below 20 degrees you should leave for at least 10 minutes, or up to 30 minutes.
3. Clean away excess penetrant
Once you’ve let it dwell you’ll need to clean off any excess surface penetrant. Use the DR-60, but this time spray it into a clean cloth and wipe over the surface. Don’t spray directly onto the surface at this stage because the spray can drive the penetrant out of the cracks and you’ll miss the flaw - a cloth will make sure the cleaner only removes the excess.
4. Apply the developer
Spray the Sherwin D-100
directly over the area making sure you cover all angles of the weld. The developer will bring any entrapped penetrant to the surface through a capillary action, to reveal any flaws.
Some obvious flaws will appear quickly, others may take longer so leave it for at least 10 minutes to ensure more accurate results.
If you see red… yeah, you’ve got a flaw, if it’s clean, you don’t have anything to worry about! So quick, so easy!