Inspecting for blemishes-tips

[Jonathan Webb]

I've been priming my beastie for ages now, as I keep finding new blemishes to fill then 3 days for 3 coats of primer.

Broadly flat/gently curving mild steel structure.

What do people use in terms of lighting- do I want floodlights, moveable directional light?
Any other tips?
Thanks.
PS. What level of panel/joint appearance to go for on a large (2mx1m) steel sculpture? It's not a concours car, and isn't meant to be scrutinised at close quarters as I'm inevitably doing. How to deal with this?

 

[gaz_moose]

I tend to look at the reflections of things on the offending surface to point out any blemishes.
if it was for instance the side of a panel van and you were inside then the a strip light would leave a nice long reflection so you would spot any areas where it would change.

 

[Jonathan Webb]

I tend to look at the reflections of things on the offending surface to point out any blemishes.
if it was for instance the side of a panel van and you were inside then the a strip light would leave a nice long reflection so you would spot any areas where it would change.

It's directly under a striplight,but because of the structure's height, one side is in shadow. I've tried moving it but its heavy and not inherently stable. It's also 5' away from a SW window and open door whuch gives good light, but this has highlighted the problem - as the light intensity changes, new blemishes come to light. Controllable illumination is key I think.
The epoxy primer is Matt and rollered and the finish will be semi-gloss so I don't have reflections to help.
Maybe a striplight wand made of LEDs would help? I've tried using a led par38 that I had lying around, but I'm wondering if less brightness would be better?

 

[gaz_moose]

id missed the part that's in primer. that will make it 100 times more difficult to see with your eyes.

if its grey primer then give it a very light dusting of black spray paint, then give it a light sanding with a long sanding block, any low spot will remain black painted whereas the higher parts will be smooth grey. assuming you are using a decent high build primer. if your using cheap spray paint primer you wont get the thickness.

I don't understand this part of your question....,,,,,"""PS. What level of panel/joint appearance to go for on a large (2mx1m) steel sculpture?"""""

 

[carbon]

As @gaz_moose has said, guide coat is the way to go with a contrasting colour either as a spray on or a dry one

 

[p0689109]

I would have thought daylight as its then that the blemishes will be seen!

 

[tommullin]

I think you want no natural light, its too diffused. The pros do this:

so they can see imperfections showing up as distortion in the lights reflection. But as said, primer is hard to see until you get paint on there.

​

 

[p0689109]

Yes but normal people will see the car in natural light and if you cannot see any if you use natural light to check then the car will be OK I would have thought.

 

[Daz1968]

I purchased a 4foot strip light and put in a daylight tube. This I move around as needed. I also used dry guidecoat on primer stages

 

[Ianb]

Wetting/wiping the surface with panel wipe will give it a brief gloss and can help show imperfections.

 

[ajlelectronics]

Wetting/wiping the surface with panel wipe will give it a brief gloss and can help show imperfections.

As can putting on that final coat of lacquer unfortunately.

 

[ajlelectronics]

Or just putting on the final coat of Satin Black and noticing that the gun has started spitting water, despite draining the whole system and having breathing air traps and filters plus the belt filter in the way. Not a happy bunny today as I have to let that go off and then redo two pieces.