Synthetic Veil

[dakazman]

 After sanding out slot of chemical stripper damage and repairing some cracks it’s time to experiment with this new synthetic veil. See pics 3-5 . Available from fibreglas.com, item 1851c , I ordered the 5 yard length.
Details are on the site , but the object here is to stop the bleed thru of the loose strands and add a better impact resistants.
  I covered a spare bonnet with ease , fabric is .01 inch thick and stretches easily when wetted out, so a lot of dabbing instead of rolling. I used polyester resin but can be used with epoxy. It’s also very flexible.
  I’ll put this on the fast track for sanding and priming as some of my paint is approaching expiration.
 Time will tell .
Dakazman
 

[GavinT]

That stuff looks good, Dave, and much easier to handle than the more common wispy continuous filament veil.

Looking at your third pic, have you tried fibreglass reinforced filler yet?
It's magic stuff for those sorts of issues.

[Richard48Y]

This company, 1581-C?
https://www.fibreglast.com/product/synthetic-surfacing-veil-1581/Surfacing_Veils

[dakazman]

This company, 1581-C?
https://www.fibreglast.com/product/synthetic-surfacing-veil-1581/Surfacing_Veils

   
    That’s the place. Richard.
 
   GavinT
   I’ll give it a go

   Dakazman

[GavinT]

Ooops . . I meant to say 4th pic.

See . . they didn't even grind out the divot – just whacked in some bog and carried on with their day.
After 50 odd years, it's clear there was little attention paid to what would be considered best practice today.

[dakazman]

  Correct Gavin,
   That’s some of the things people slap together. That’s all the more reason to strip paint off completely.
  I also repaired a door with severe stress cracks  all with mat glass fiber. I stay away from the canned body putty mixes . I just couldn’t take it hanging around my garage without making it useful.
It was a great way to fill some time in, and using up products. This one will be coated in the stranded veil.
Dakazman

[dakazman]

  Okay, I’m calling this a failed test .
 
   One not that I forgot to add a contrast agent so that I absolutely knew when I was sanding off the resin that the veil was untouched.  ADD A CONTRAST AGENT.  I will bring that up with fibreglas.com maybe to add a color to the fabric.
I work on the visible air pockets that I didn’t sand off the veil .
  I have another piece, a door but it still needs more work just to get to veil status. 😂🥱
  Stayed tuned,
Dakazman

[kram350kram]

Just recently veiled almost every surface on my TCS. Repaired bad locations first as you are... pinholes, voids, soda blasted pits, etc... . I did find that less resin is best. Used to much resin on my first veil attempt, the hood and I paid for it with a lot of sanding to get a smooth and even finish prior to high build primer.  I  found that using peel ply helped minimized sanding and resulted in a much smoother surface. The engine hatch, fenders, doors and rear quarters were all much easier to finish prior to primer.  Peel ply is another step but for me was worth the time as it reduced my sanding/finishing time. Best of luck.   

[GavinT]

  Okay, I’m calling this a failed test .
 
   One not that I forgot to add a contrast agent so that I absolutely knew when I was sanding off the resin that the veil was untouched.  ADD A CONTRAST AGENT.  I will bring that up with fibreglas.com maybe to add a color to the fabric.
I work on the visible air pockets that I didn’t sand off the veil .

G'day, Dave,

This isn't a failed test; you've learned something. 
A contrast agent sounds like a good idea to me but I wouldn't be taking FibreGlast to task.

These veils are intended to be used as the outermost layer for the production of an in-mould composite part and not for glueing to the exterior of an already existing laminate as we are doing.
You and I are using these products out of spec – link below.

http://www.fiberglassfiberlink.com/assets/v1-v2-fiberglass-surfacing-veils.pdf

And you've highlighted a point that always bothered me. Given that veil is so thin, how is it possible in the real world to avoid sanding through the veil while also looking to achieve a decent surface. To me, those are the competing objectives.

Are you referring to those white spots on the bonnet as "visible air pockets? or are they high spots.

[GavinT]

Hi, Kram,

I agree less resin is best. As an experiment, I thinned down the resin with acetone and that worked OK. I still found it laborious to eliminate air bubbles because a fin roller kinda skips over the hard surface. I haven't tried one of those 'bristle' rollers, but that may be better.

Another experiment is going to be applying veil with spray polyester filler like Slick Sand instead of standard polyester resin.
In my mind (always dangerous), I can see that as a more amenable product for achieving a suitable sanded surface and perhaps doesn't lack much in terms of discouraging the print through of micro-cracks and other small defects because the veil remains intact.

[BDA]

[deletia]
And you've highlighted a point that always bothered me. Given that veil is so thin, how is it possible in the real world to avoid sanding through the veil while also looking to achieve a decent surface. To me, those are the competing objectives.

I'm no expert and my fiberglassing job may have exceeded my skill level but I considered the veil as sort of a "carrier" or holder for resin (with the veil providing some tensile strength to protect against future cracks). So, in a way, I considered it sort of a replacement for gel coat. When I sanded the veil after the resin cured I used pretty fine paper (I don't remember what grit I started with) on a dual action orbital sander. As such, my aim was to sand the resin rather than the veil. I didn't do anything to thin the resin. In fact as long as it was thin enough to spread with a brush (probably not very thin) and wasn't in danger of kicking, I was fine with it. I used the brush to stipple the veil/resin to smooth it and get rid of any bubbles.

I have to admit that I did all this over twenty years ago so my memory of my theory of what I thought was doing could be better than my memory of how I actually did it.

After over twenty years, it still looks good though very close examination reveals some very minor imperfections that I don't believe were there in the raw fiberglass when I gave the car to the paint shop. I have no explanation of how they got there and could be the result of my lack of understanding fiberglassing.

So my question is , "Does my theory that the veil is to a great extent a carrier or holder of resin make any sense? Or am I off base and I should be glad it looks as good as it does?"

[dakazman]

Gavin, not a failure with material but rather my procedure. This is appropriate for topical adhesion. see data sheet. The wet thru was extremely fast causing the air pockets. usually come out when poked with a paint brush however the veil seemed to dense to puncture, even afterwards tried poking with a needle , no help.  they are in the lower glass fibers.   
   I can now see the difference in layers , the veil looks blurry or cloudy if you get close. I wrote to the company about a different color or maybe adding a tracer line throughout the veil.
 
                  https://s3.amazonaws.com/cdn.fibreglast.com/downloads/00430.pdf

  Kram , I pulled up the peel ply product , very interesting and definitely a time saver according to the video online at fibreglast.

  BDA, finding hairline cracks with the naked eye is very difficult. water gets in and if your in a cold climate will slowly lift and get deeper.
 Dakazman

[dakazman]

   Just posting some pics of the composite veil and what it looks like. I will be comparing it to the continuous strand .
  I also coated a defroster grille that I’m fabricating , it worked well and I’m getting use to working with it.
Dakazman

[GavinT]

This is appropriate for topical adhesion. see data sheet.

Dave,

Nowhere does it mention the words "topical adhesion".
The Fibre Glast data sheet says:

"Adding a polyester surface veil ensures superior impact strength while acting as an exceptional cosmetic print blocker. Use this veil as a surfacing layer on laminations to extend the life of your materials".

It's perhaps a matter of interpretation but I'd suggest they're promoting the 'inclusion' of a surfacing veil during the process of laying up the laminate i.e the originating wet process.
I don't believe they're suggesting a subsequent process of adding veil onto an already cured laminate.

Owens Corning, an actual manufacturer of various veils, says much the same thing. They talk about veils in terms of being  "used in a variety of composite manufacturing processes". From my research, all manufacturers say similar things.

https://www.pressreleasefinder.com/prdocs/2003/Product_Information.pdf

I'm not looking to be 'that guy' and would love to be wrong on this.
Do Fibre Glast have a recommended procedure for applying veil to an already cured laminate as we are doing?

[GavinT]

So my question is , "Does my theory that the veil is to a great extent a carrier or holder of resin make any sense? Or am I off base and I should be glad it looks as good as it does?"

Tricky question, BDA and I'm no expert either.

I don't think your theory can be easily refuted but the overarching question from this devil's advocate might be; "to what extent does adding a resin rich layer with the claimed minimal reinforcement properties of veil benefit the laminate structure overall".

The answer might be; "just enough to mitigate a good number of the hitherto unseen micro-cracks even though we accidentally sanded through the veil in some places".

An alternate answer might be; "provided the veil remains intact and does the intended job, the minimal addition of resin is of insignificant detriment compared to the overall benefit to the laminate as a whole".

I reckon either way could be argued.
That probably explains why it bothers me . . but I use veil anyway.