New window sealing question.

[Hoohaa]

Also, regarding paint. Has anyone has experience with the silicone-based, high-temperature exhaust paint for hiding and protecting the Grey 3B tape? Or maybe some other recommendations?

[PegasusIX]

I had paint on some of my windows. Plastic or Acrylic paint. I note that where it is exposed (ie not under tape) on the inside of the window it has deteriorated and now powdery. I understand many paints don’t have adequate protection to UV light exposure over the long term. I wonder if same effect is happening under the VHB tape affecting the bond. Other windows done without paint under VHB with black tinted acrylic, and tape can’t be seen. So I would avoid painting where window is to bond as there is no benefit in appearance, and increased risk of deboning over time as paint is affected by UV light and heat.

[Greg4cocokai]

Originally Posted by Hoohaa

Sounds good. What was the bit diameter?

Mine was 1/2". They have different lengths, bearings on top or bottom.

[SharkBite]

Originally Posted by svquintana

I just did these today. Grey 4991 and Dow 795. There is a 4991B (black) but I had no luck finding it. The plexi is the darkest available, and the tape doesn't show through.

https://industrialtape.com/catalog/p...-vhb-tape.html

Click "specification" and you'll see the colour is black.

Thanks Paul. that little 'B' makes all the difference. I've gone back to the UK distributor to see if that's available here too.



Nice job on your windows. I'd like to replicate that on my project - the continuous black strip, as I dont have rebates. I'm hoping to get the black tinted perspex soon.

[GRIT]

You're welcome. Glad to be of help.

The perspex tint is "2074" which is the darkest Grey tint. The slightly less dark Grey tint is 2064.

There are also two Bronze tints.

Good luck with your project. If I can help, just let me know.

Cheers.
Paul.

[john61ct]

UV rays don't slide in under the VHB tape.

[Hoohaa]

I Just Picked up my sheet of 10mm Acrylic sheet and placed my order for
3M VHB 4991 Tape 24mm wide. I had to buy a full 33m roll of the Grey So I will have at least 20m or 65' left over if anyone is interested?
Due to the colour (Grey) I am seriously considering painting the back edges of the acrylic, but am having a bit of trouble tracking down the right product.
I have looked at whats available int the local car parts shop but its difficult to know if the Exhaust paint is silicon based or not? Can anyone recommend a product?
Here's a pic of the slab of Acrylic. More to come.

[SharkBite]

I've just put in an order for mine, after making a specific initial enquiry - only to find out they can only supply 3mm and 5mm sheets!


The search continues.

[Hoohaa]

Took the first small window out today as a test piece and to see what was hiding underneath.
A couple of cosmetic problems inside but I got luck outside as there's 10mm of solid fiberglass around the window. No core, just a thin ply veneer stuck to the inside of the fiberglass.

[Hoohaa]

The window almost fell out when I undid the screws

[Hoohaa]

First pic shows the glass width once it was cleaned up.

[Hoohaa]

Originally Posted by Greg4cocokai

Mine was 1/2". They have different lengths, bearings on top or bottom.

Greg.
When you used the router. Did you cut the sheet down first, so that you were just doing a say 1/4" cut the edge? Or did you just dive right in, using the bit to cut the full shape out of the sheet?

[Hoohaa]

Ie. Did you trim this down first?

[mikereed100]

Originally Posted by Hoohaa

Greg.
When you used the router. Did you cut the sheet down first, so that you were just doing a say 1/4" cut the edge? Or did you just dive right in, using the bit to cut the full shape out of the sheet?

Do a rough cut with a jigsaw leaving a 1/8" or so margin, then finish off with the router, using the old window as a template.

You may want to consider thermoforming and annealing the windows to achieve the bend as this will result in less stress on the acrylic and decrease the tendency for crazing.

[Greg4cocokai]

Originally Posted by Hoohaa

Greg.
When you used the router. Did you cut the sheet down first, so that you were just doing a say 1/4" cut the edge? Or did you just dive right in, using the bit to cut the full shape out of the sheet?

I bought mine a half inch oversize, hauled them to Mexico, then just cut them down with the router bit. You can carefully take a torch and melt the edges clear. There is a YouTube video about replacing hatch lenses that shows how to do that. But be careful!

You can see how the Dow 295 is being squished in the corner. It's 30° hotter here than where I installed them.