Fibre glassing

[Psycho pops]

Gary hope your reading this!
Had my first go at the black art of fibre glassing tonight, started on the small compartment I am making as I new this would not be seen, my question is when covering a corner how do you avoid an air bubble forming when you lay down the matting, I tried rolling , stippling and stretching the matting but each time it still made a pocket over the corner, is this avoidable ?
Would like to get a little more skilled before i bond on the body any pointers?
Cheers Pops.

[tlrtone]

I had a quick master class from Mike when I went down there last week.

1. Mix up some bonding paste and some resin, you will use both.
2. paint some resin in the corners and along the edges as that will fill any voids
3. Rip up some lengths of matting don't cut it straight or you will get an edge
4. Pre-Soak some matting with resin on a seperate flat surface as it will make it a lot easier to manipulate and stick
5. Place your soaked matting where it needs to go and push it into the corners and edges onto the bonding paste. The paste will help it stick and fill the voids.

Well that's the theory!

[lancelot link]

Originally Posted by Psycho pops

Gary hope your reading this!
Had my first go at the black art of fibre glassing tonight, started on the small compartment I am making as I new this would not be seen, my question is when covering a corner how do you avoid an air bubble forming when you lay down the matting, I tried rolling , stippling and stretching the matting but each time it still made a pocket over the corner, is this avoidable ?
Would like to get a little more skilled before i bond on the body any pointers?
Cheers Pops.

Its a little difficult without seeing the job , but the thing with that sort of glassing job is to not rush , cut smallish pieces of mat - dont try and do it in one or two bits . Also you need to keep it wet , use a bit of paste or even body filler in an awkward corner to grab the mat . . . you also need to not randomly just keep rolling all over the job chasing the bubble but tease it out the edge of the mat . . hope that helps . . . . the body layup is easier than m

[chrislandy]

Building on what has already been said, when doing complicated work (internal corners and double curvature) with a stiff brush and stippling, work progressively across the part in rows working side to side so you don't disturb the areas you've already worked on, take your time and do some test pieces with different catasyst ratio's to see how much working time you have. Complex parts need more working time so try 1% by weight with poly resin rather than 2%.

I bent a bit of aluminium into an L-shape, put a few layers of release wax on it then 450csm and practiced until I got the hang of it without wasting any moulds I've made. You need to make sure the csm is fully wetted out and the bonding agent has disolved before you work it properly

[Mister Towed]

I just winged it and it seemed to work.

Apart from when I got the catalyst ratio completely wrong and the flowcoat didn't set.

[cbjroms]

Having done quite alot of fibreglass work on previous projects I thought that I knew what I was doing.

Not one to throw things away, my first few Sammio fibreglassing sessions made use of the West Epoxy that I had lying around the garage and this worked fine.

But I was looking forward to starting afresh with the Polyester resin that I bought for the Sammio. First job was to put another layer of mat to strengthen my bonnet modifications and to re-inforce the battery tray which I have reduced in size. But next morning I found that the resin had not even started to think about curing.

Spoke to my supplier who was convinced that I must had got the mix wrong but then I mentioned the West Epoxy and all became clear. You need to leave West Epoxy for approx 3 weeks before covering with Polyester or the latter will never cure!

Spent a few happy hours last weekend removing the uncured Polyester, grinding away the cured Epoxy and going again with the Polyester.

Chris