Help with fibreglass

[Phill @ Elite Workwear UK]

Hi, I am looking for a little advice on fibreglass and resin related products, techniques and suppliers.

we have acquired a show trailer. It has some damage to one side, a little like a tin opener gouge. This needs to be patched over. I also want to alter the layout a little, it currently has one full opening side. I want to close this off and have a door and window. Some of the original walls were thin ply skinned with fibreglass but water has got in and delaminated and rotted. I have removed all of the roted wood but need to repair and strengthen the fibreglass. Has anyone got any idea where to start as I have never done this before. Will I need a large quantity of glass and resin? How do I go about making it smooth on the outer surface as I have no mould to work with.

Any help would be very useful.

Thanks

Phill

[fly boy3]

Hi Phil, I too knew nothing about fibre glass work. Needed to fill a large hole in garage roof. I was told to go to Halfords where I bought a fibre glass kit. The kit was enought by far for what I needed and all the instructions were enclosed. Very pleased with the result too. You could practice on a small area first if you have enough. Cheers

You can also find videos  on this subject on utube.  Take note of any Health and Safety instructions you may find on kit.  Good luck.

Edited By fly boy3 on 15/08/2013 22:56:08

[kevin b]

Hi Phil. Don't know whereabouts you are, but I would try and find a local boat builder if possible. They are very clued up on this type of work. Most of the smaller ones will be happy to spend time talking to you and advising what to do. This is my experience anyway. You may find that they will work with you on the project for a very reasonable sum and trust me it will be worth it ! the materials are not expensive, but doing a good job in fibreglass only comes with experience. I have had a considerable amount, but someone who works with the stuff all day can do the job in half the time, use half the materials and do twice as good a job as me (with a lot less mess).

kevinb. ex kitcar manufacturer/builder.

[Colin Evans 1]

Hi Phill.

Try looking on the net for grp suppliers, such as CFS Fibreglass for instance. You need to figure out the approximate surface area of your repair to be able to guesstimate material quanties. Also it depends on the level of finish you want - slapped on bandage v invisable repair.

As a rule of thumb, for lay-up resin, you'll need 2.5 times the total weight of matt if you are using chopped strand matt (CSM) or 1.5 if using woven rovings (WR). Matt comes in grams per square metre. The heavier the matt the stiffer it is. A general multi purpose weight would be 450g to 600g which I think would suit a flat trailer side. Therefore if you have 1sqm of 600g csm then you will require (2.5 x 600) 1500g of resin. The catalyst is usually supplied with the resin and is added at a ratio of 1 to 2 percent by weight. ie 15g to 30g. Note that 1sqm of 600g WR would only need 900g of resin. For the glossy exterior you need gelcoat. You can get clear and add pigment or buy pre-pigmented. If you want to use the gelcoat like a paint then you have to add a wax solution or you can buy it premixed, called flowcoat. Gelcoat/flowcoat uses the same catalyst as lay-up resin and at 2 percent by weight. Generally, allow 300g of gelcoat per square metre per coat.

If it is a flat panel to repair then you are in luck. Taper the edges of the hole with a grinder/sander. Use some cheap formica faced board for a mould and use a PVA release agent and/or mould release wax to stop everything sticking. Attach the mould to the outside of the hole. Apply 2 coats of gelcoat from the inside on to the mould then lay up over that with alternating layers of csm and wr, starting with csm against the gelcoat and going over the tapered edges of the existing laminate. If you have already replaced the plywood on the inside then lay up the matt from the outside on to the new ply and then apply a thick coat of flowcoat. Once cured, wet and dry sand and polish.

The thing with this sort of work is that you have to buy consumerables. Some brushes, one or two consolidating rollers, clean mixing pots, scales, scissors, disposable gloves etc and a catalyst dispencer is really handy. Not to mention the sander, sanding pads, dust masks, acetone etc

Hope this helps, good luck!

[Joe Beavis]

The first attempt at a fibreglss job may suggest that it is impossible! It gets easier, though. Try something small first, to get the feel of the materials and techniques. Do read up about it, and don't start the big job until you are sure of how you are going to do it in detail. Watching a pot of resin going off (and its not that cheap) because you hadn't planned properly is an excruciating experience. Good luck, Joe

[Steve Hargreaves - Moderator]

I have used these guys in the past...they were very helpful on resins & cloth weights to use.

It is pretty easy to achieve a satisfactory result with glass cloth & resin.......mix the resin...apply it to the surface you want to coat & then lay the cloth onto the resin....add more resin to fill the weave of the cloth....apply extra layers of cloth as required.....leave to set.

Thats pretty much it & will give a satisfactory result.....good enough for your trailer I would suggest...

To achieve a good professional finish takes considerable skill & experience however....

[Phill @ Elite Workwear UK]

Thanks Guys,

I have found a company that can supply pre-covered plywood panels for the BIG are we need to cover/replace so that will make it much easier.

Flyboy - I have had a look at the kits on the Halfords web site and they look quite useful. I may pop in when I am close by and have a better look.

Kevin B - I have had a look for a boat builder and there is nothing local really.

Colin - Thats great info - thanks - I will have a look for the places you suggest. It is a little more complicated than I had first thought.

Steve - I have had this place sugested by a friend who has burger vans and often uses them to get repair materials.

It is going to be a little while before I can get back onto this as the Nats will be taking up all my time this week and some of next. I will report back with my findings.

We are having a exhibit at the Nats this weekend so if anyone is there please feel free to pop in and say hi.

Cheers all & hope to see some of you over the weekend.

Phill