Fibreglass resin vs casting resin

[BoomerangInfo]

So I'm in Bunnings today, killing time while the missus is at a meeting, and tried to checkout their casting resin vs fibreglass resin, which was 20% cheaper for the same pot size. It's Diggers brand, so looking at their web site, this is what I found.

Fibreglass Resin
Unsaturated polyester resin (non hazardous) (45 -75%)
Styrene (24 -54%)
Methyl methacrylate (1-8)

Clear Casting Resin
Polyester resin (30-60%)
Stryrene (30-60%)
Additives (1-9%)
Other solvents in very low proportions (1-9%)

Given there's some wide variations in the percentages, and they specify the same level and type of catalyst, I reckon they're pretty much interchangeable, aren't they?

The only thing I don't know if if the Fibreglass resin is clear, which may be the sticking point. It may be some murky colour which may or may not be able to be tinted, but would be no use for embedding actual items in that you wanted to see through the resin. Anyone used Fibreglass Resin that knows, or can see any other reason it couldn't be used instead of the clear casting resin?

Thanks. Russell.

*EDIT*

Just found this info as well for Fibreglass

• Wax has been added to the resin to
stop the fumes entering the
atmosphere.
• A pale amber liquid with an aromatic
odour.

Not sure what that may mean for the end result though.

[Big Shed]

Fibreglass resin is designed to cure in thin sections/layers, unlike casting resin whicj is desgned for curing in thick sections.

They are definetely not interchangeable.

There has been some discussion on this subject on this and other forums, people have not been happy with the results obtained with casting fibreglass resin.

[BoomerangInfo]

There has been some discussion on this subject on this and other forums, people have not been happy with the results obtained with casting fibreglass resin.

Darn, guess it's back to the expensive stuff then. The Casting Resin says to do in 5mm layers as is, which is a problem already, although I did at least 15mm at once without any obvious problems. Guess I'll just have to wait till I can get to the big smoke and try and find some proper stuff.

Russell.

[corbs]

You don't want to turn the Diggers casting resin... its bl:oo::oo:dy hard. I used it to fill some voids in a bit of rosewood a while ago and it wasn't fun to play with.

[dai sensei]

Fibreglass resin is not clear, but works Ok for solid pigmented colours. The casting resin is better for larger sections, but both shrink and crack if too much is used in one hit (but both accept extra resin to fill the cracks).

[BoomerangInfo]

You don't want to turn the Diggers casting resin... its bl:oo::oo:dy hard. I used it to fill some voids in a bit of rosewood a while ago and it wasn't fun to play with.

Er, that's what I used to do the two samples I've posted elsewhere. Seemed fine to me, no trouble turning at all. Maybe it depends how much catalyst you use? But anyway, it's all I've been able to get locally. As soon as I can source some proper stuff somewhere else, I'll change anyway.

Russell.

[corbs]

Ok then... will get back in my box now:-

[BoomerangInfo]

Ok then... will get back in my box now:-

No please, stay on your box. You're keeping the sun out of my eyes.:D Besides, I'm hardly the expert in this area. What's it say on all the latest games now? "You're online gaming experience may vary?" Something like that, anyway.

Russell.

[Big Shed]

Darn, guess it's back to the expensive stuff then. The Casting Resin says to do in 5mm layers as is, which is a problem already, although I did at least 15mm at once without any obvious problems. Guess I'll just have to wait till I can get to the big smoke and try and find some proper stuff.

Russell.

Russell, the Barnes Quality Casting Resin I use I have used in failry large sections, for instance I have cast a 30mm diam x 30mm long section for a knob on my lathe, I regularly cast 165x100x20mm blocks whic I then cut up on the bandsaw in to pen blanks. Same with the Clear Casting Resin.
As stated above, you do get some shrinkage, but that makes it easy to remove from the mould.
For the mould for that size block (makes it much easier to get swirls etc) I cut up a HDPE cutting board and screw it together with small screws.

I use 30 drops catalyst per 100 grams of resin (use digital kitchen scales) in the colder weather, but I may have to cut that back in the warmer weather.

Barnes sell the catalyst (MEKP) for $7.70 per 100ml.

[BoomerangInfo]

For the mould for that size block (makes it much easier to get swirls etc) I cut up a HDPE cutting board and screw it together with small screws.

I'd been thinking of doing that, and had seen it mentioned elsewhere. Do you manage to get it together OK without any leaks? I'd been using some plastic food containers to date, but it's slightly tapered and has a small indentation in the bottom, so there's a bit of wastage. I also cut one up to partition the container in half, but being a flimsy material, it's hard to get a proper partition, and I did have some minor leakage due to that indentation I mentioned.

The other easy option for me may be to make it in wood and line it with something so I can get the resin out again. I'm trying to go for flat moulds I can work with more than pipes, which have limited workability, although will probably end up with both in the end.

I'm trying to get a shipping quote from Barnes, but it seems to be around $30 - $50, which increases the cost significantly. I also tried to email armsmodelit, who are closer, but their email is bouncing.

If anyone knows a supplier in Toowoomba, which is my nearest major centre, let me know. It's a $25 petrol trip, but can combine it with some other shopping as well, so it sort of reduces the transport cost. I'm 90% sure I can't get anything much besides the diggers stuff in Warwick.

Russell.

[salty72]

To fill voids in burl I use kenetiX R103 with H125 hardner - If you buy the 6ltr Kit (4 Resin and 2 Hardner) it is around $120. The mix ratio is 100:43 by weight and 2:1 by volume. It has a pot life of 25mins and accepts pigment dyes, is Ultara clear and UV stable for 15+years

just a thought

[Big Shed]

I'd been thinking of doing that, and had seen it mentioned elsewhere. Do you manage to get it together OK without any leaks? I'd been using some plastic food containers to date, but it's slightly tapered and has a small indentation in the bottom, so there's a bit of wastage. I also cut one up to partition the container in half, but being a flimsy material, it's hard to get a proper partition, and I did have some minor leakage due to that indentation I mentioned.

Russell.

I sanded all the parts on the disk sander after cutting on the tablesaw but had a slight leak in some places, nothing to worry about though. First cast came out without taking it apart, so leaks disappeared after that.

I also left the slight texture on the cutting board, which makes the cast easy to remove, especially with the slight shrinkage.

[Skew ChiDAMN!!]

I prefer a simple tray lined with kitchen alfoil.

The foil can be a bit of an annoyance if not properly smoothed flat, but is quickly turned off if it sticks.

[Sawdust Maker]

How do you do the swirls?
drop in the contrasting (whatever) and give a bit of a stir, bit like the fancy cappuccinos?

[BoomerangInfo]

How do you do the swirls?
drop in the contrasting (whatever) and give a bit of a stir, bit like the fancy cappuccinos?

I'll tell you when I get some that work :)

I'd think swirling would be slightly more of a problem with a foil lining - you'd tear it pretty easy if not careful.

Russell.

[GazzaR]

I've used the hardware store Diggers casting resin, worked OK. As I used a silicone mould set up to cast around the tube, the section thickness wasn't much more than 5 mm. It is fairly brittle so chipping when turning can be an issue, you have to be careful. Keen to try something else (at this stage only interested in clear casting). Appreciate the info as to other options on here.