Synthetic Veil

[dakazman]

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?

 Gavin , Thank you first of all .
I post all these concerns to them. I jumped the gun so to speak, I watch their video and they mention laying up “next to “your laminate.
  I have asked about a tracer or a contrast agent, no word back yet .

I did put in another order for some 60”regular Matt and some peel ply.  I’m basically just playing around with these panels that we’re headed for a dumpster. Well they are far from dumpster quality now with just running thru initial repairs.
  My objective is to get them into a primer state before my paint expires.

  BDA,About tensile strength…, I did a very non scientific test with a dynamometer, pulling a piece of the composite saturated with one coat of resin .  Poking a hole thru the single layer I achieved a 18n or 1.8 grams. Which is about equal to a single thin rubber band. It surprised me when I tried to pull apart by hand though.

 

[BDA]

If I understand your tests, D'man, I'm not surprised. Tensile strength should be a lot stronger than resistance to poking through. That's part of the idea - to provide tensile strength to a substrate that lacks it.

I agree with Gavin's answer to his question

"to what extent does adding a resin rich layer with the claimed minimal reinforcement properties of veil benefit the laminate structure overall"

that there is enough to suppress the formation of spider and star cracks. Obviously veil will not lend much strength to the underlying structure but there is enough tensile strength to prevent (most of) them. I also think it can help fill very minor imperfections in the underlying surface (previously mentioned minor imperfections noted in my car notwithstanding).

Somewhere I got the idea that prepreg veil might be part of the conversation. Is it? I would think that would be very difficult to manipulate!

 

[dakazman]

  After working with the composite veil I’ve found it nearly bulletproof. Sanding with 120g normally would cut through glass fiber easily, not so with this polyester.  So I went back to to data sheet it says abrasion resistance, absolutely passed this test .

https://s3.amazonaws.com/cdn.fibreglast.com/downloads/00430.pdf

   Explaining polyester,  https://youtu.be/XuEqieNcfac

  Here are a few pictures of hairline cracks. Showing the importance of sanding the paint off completely on both sides and holding up to a light, in this case the sun. Adding the veil can probably save a paint job , these still need to be addressed before covering.
 The hairline cracks start to chip out when the lines get close to each other, not to mention what freezing water does to them.
  Fiberglass and bondo to fill a crack, no way, see pic .
Dakazman

[dakazman]

 BDA,
  Here is my next test of continuous strand 260H veil from fibreglas, that I'll be using. It does not have add any tensile strength, but does improve appearance. that is probably what you used back when. I agree that some type of covering must be used and that is what this thread is about. We have a problem with deterioration, strand separation, etc.
     This test will be on a door and not a panel that water lays on, the sides of the car don't seem to have the same problems as the top sections .I'll be using it on the doors. After seeing how strong the composite veil was I may add it to the door jamb area that suffers a lot of abuse from the hinge area.   

   https://s3.amazonaws.com/cdn.fibreglast.com/downloads/00092.pdf

  Dakazman

[BDA]

I think of using veil for protecting against surface cracks forming and to provide a good smooth finish. Those aren’t problems you find in the door jamb so I’d tend to limit using veil to external surfaces.

When I said I was no expert, I meant it!  I got my veil from r.d. I got my mat and resin from Lowes. The discussion about synthetic and continuous strand veil etc. is really beyond me!

[TurboFource]

Not looking forward to this part of my project.....

[BDA]

Relax, Turbo! I did some reconstruction on my car as well as some modifications and nothing has fallen off yet! There is science to it but I was able to do my work without knowing it. There are a few simple tricks but it’s very simple and forgiving. I enjoyed the fiberglass work I did on my car. The worst part is how itchy you get.

[dakazman]

   I did it again, I mentioned door jamb area.  Thinking about the door pins and damage that occurs on the inner door area when things go wrong when doors start hanging down .I’m no expert either Gavin but just stating my experience.  I’ll post pics of the 3 doors and the locations of the damaged areas.
   BDA and turbo, let me pass on one good thing about trying to sand down this composite veil is that it’s polyester and not itchy.  The continuous probably is itchy because it’s glass .  It is tedious, so I jump from cutting and beveling out on a few pieces to layup on others then back to inspecting and grinding or drilling.  That way if you mix up to much resin you can touch up things you missed on another panel or area.
   Tomorrow I plan on painting some clear coat on my bonnet, I was waiting for the perfect day when the weather was perfect. It’s the second coat after sanding out some shrinkage.

Dakazman ,

 
 

[GavinT]

Appreciate your candor, Dave. - we're all learning.
I'm liking that polyester veil.
My trouble is I have the vast remains of a 100 metre roll of 80 gsm continuous filament veil that I really should use up . . decisions, decisions.

  Here are a few pictures of hairline cracks. Showing the importance of sanding the paint off completely on both sides and holding up to a light, in this case the sun.

Absolutely . . . and it's why I'm a fan of sand blasting.
I suspect people think I'm mad for doing that but are too polite to say so. 

For those interested, below is a pic showing the use of a light woven fabric which fixes surface cracking just fine but also prints through the final paint job . . we live and learn.
In the lower middle of the pic is an area of cracking that was missed and thus, not treated.

My updated repair procedure for these non-structural cracks is to grind them out to the customary saucer shape and fill with 'Kitty Hair'.
Evercoat do a variety of these reinforced fillers. I've only used the heavier duty 'Kitty Hair' variety but might try the lighter 'Glass-Lite' product.

EVERCOAT Fiber Reinforced Fillers & applications YouTube video.
https://youtu.be/tY3E0ztz8SY

[BDA]

For those interested, below is a pic showing the use of a light woven fabric which fixes surface cracking just fine but also prints through the final paint job . . we live and learn.

Been there, done that... well had it done... Back when my car was "new", as part of an accident repair, I had a guy cover the whole car with fine cloth on the theory that future crashes would be easier to fix if all the pieces were recovered and cloth would help keep the pieces attached to the car. Ignoring for the moment the psychology of planning for the next accident, we found that there was nothing that would get rid off the cloth printing. I suspect that covering the cloth with veil might have worked but I didn't try it (it didn't look like the guy covered the doors, boot, or bonnets with cloth - the parts I covered with veil.

The cloth printing is not obtrusive but it's still there. Live and learn indeed! It is never a good idea to use cloth where a nice finish is desired!

If you don't itch when sanding the synthetic mat or veil, that's a great reason to use it!

[dakazman]

  I worked on a few more pieces today using up what I have laying around. The repaired panels are not ready for the veil yet. The composite veil is showing great promise, after cutting out all the void’s below the fabric.  I put my resin glass slurry to work filling the holes  Thinking about another layer of the composite but slowly rolled onto the surface underneath.
  I had a little 4-1 high gloss clear coat to use up so as previously mentioned the bonnet was sanded down with 800 grit , not penetrating thru the clear but just removing the fabric strands that showed through after being shrunk-wrap by the clear a year later. I’ll post more pics after nibbing out and polishing up.
  Happy with the renewed surface but I can’t say how long it will stay perfect.
Dakazman

[Kendo]

That makes a whole lot more sense. With your talking about the synthetic veil, I thought you were going to shoot clear on it for some reason 

[Richard48Y]

Disappointed to find this, "Binder is not compatible with any epoxy. PLEASE NOTE: It should be used with polyester or vinyl ester resin only".

Just put in a large order but had to go with the other veil.

[dakazman]

  Good point Rich, Glad you caught that. So you went with the composite over the continuous strand?
  If using epoxy resins, have you had a problem with the finish? Why use veil at all ? I don’t use epoxy at all , that’s why I’m asking.
  Dakazman

[Richard48Y]

I will know once the supplies arrive and the weather warms.
My intent is an epoxy and veil final outer layer in the hope of preventing future spider cracks.
Maybe I should mention I also sprang for vacuum bagging supplies?
Years ago I worked at Omohundro spars as the Mast-Head specialist.
Sailors may be familiar with the company.
That job provided a lot of experience working with Carbon Fiber and lamination/repair technique.
CF and 'Glass are similar enough to be worked almost identically for our purposes.