Joining 2 laminates

[Leon01323]

Hey,

Not been on in a while as have been building many things and have been flat out. Been building this for a clothing company for promotions:





its for www.shatteredindustries.com and is a suit one of their guys gets in and walks around in.

Anywho my question is what is the best way to join to laminates together... Im currently making a fibreglass mountain board ( like a giant skateboard). ive got 2 separate moulds im going to make one for the bottom of the deck and one for the top both of which need to be smooth. Is this a case of laying up both sides and whilst wet clamping them together? ( would that even work?) or can i get away with letting them cure and using a joining compound?

Thanks in advance for any help

[CatBuilder]

Make sure the mating surface is as flat and level as you can get it...

then...

1) Mix up some structural bog
2) Apply bog liberally on the side that is the most lumpy/uneven
3) Carefully position the parts so they are where you want them
4) Wrap a vacuum bag around them and hold a vacuum until they cure

That should do it with the best and most reliable results.

[Leon01323]

Hey Catbuilder

Thanks for the quick response, in the shame of sounding totally inept, What is "structural bog" or how do i make it?

where i buy my stuff they have these " http://www.cfsnet.co.uk/acatalog/CFS...ASTES_288.html "

Also the other problem i have is i dont have access to a vacuum bag and as this is a trial i dont want to buy one for it just yet.

Thanks

[CatBuilder]

Ok, the poly bonding paste would work well too, it would seem. Have you done the rest of the laminate in poly to ensure compatibility?

I suppose for the trial model, you can just clamp it, as you had first thought, as well as put a ton of weights on.

But... being a snowboarder since the mid 1980's and a skateboarder since before that, I know how important it is for your laminate to stay together if you use this board. If there is a problem and a delamination happens, someone could die. That is why I was suggesting bagging the halves together. It makes for a much better bond. If you aren't going to put this first model into full use, then clamping and weighting it down will be good enough, I suppose.

Structural bog is similar to that poly bonding compound you have locally. To make it super strong, you also add glass fibers in. It's just epoxy (in many boat building cases) with thickeners. I think you could use that poly bonding compound provided the whole board is poly.

For a laugh, take a look at this giant skateboard wipeout, used on a mountain:

http://www.youtube.com/watch?v=KU1qSSZDPws

[Leon01323]

Hey

yer all i use is poly stuff be it the gelcoat or the resin so thinking that will be ok in terms of them not eating each other.

Ive already got a no sno board which are fibreglass

http://www.extremekites.co.uk/main.p...&content=index

The trucks on them are very robust and really simple.

Im thinking its gunna need to be thick and strong and was thinking about doing 2 layers of 300 gram with this "sphere core" sandwiched in-between for each side and then obviously them both joined together. its that or maybe 5 or so layers of 600 gram but would have to do it in stages to keep the heat down.

http://www.cfsnet.co.uk/acatalog/CFS...ecore_383.html


local shops do these vacuum bags for cloths that you can attach to your vacuum cleaner, dunno if they would be any good but may be worth a shot. Obviously real vacuum bags have alot more suck.

what do you reckon.

Ahha that skateboard is amazing. would love to get on that

[CatBuilder]

I've tried it and had poor results.

The shop vac (industrial vacuum cleaner) is OK for pulling down some basic things using polyurethane sheeting/tarps, but when it comes to doing it well, it's not up to task.

I tried bagging a portion of my boat's dagger boards using a shop vac and the results were mediocre. I had the same problem you are facing - two flat halves to join down the middle. That's why I responded to this thread so quickly. Fresh on my mind.

Anyway, the vacuum cleaner bagging left the joining paste (or bog in my case) at 2mm thick and left a small gap around the edge. Not enough vacuum.

On the rest of it, I used inexpensive polyethylene tarps and Liquid Nails (construction adhesive in a tube) to seal the tarp into a bag. However, I used a real vacuum pump on it that pulls 29.9xx Hg. It bonded beautifully with no gap and even squeezed all of the bonding paste out the sides. A huge difference.

Enough polyethylene sheeting to do a hundred of your boards and the construction adhesive to go along with it would probably cost $200 in the States. An acceptable vacuum pump (simple HVAC one) would cost around $300 in the States.

If you are making a lot of these, it would be the most cost effective and best results.

Cool products you are making.

[Leon01323]

Hey

Yer i was trying to say this to my mate that they cant pull as much as a proper set up with a vacuum bag. As you say if i do this in the long run then its gunna be a good idea to get one but for the trial days i think i will try find away or try and borrow or rent a pump and bag.

Thanks again for this info has really saved me alot of trouble and money figuring it out.

Cheers

[SamSam]

You might want to think of using something besides "glass" cloth for the laminate. All those joints are sure to have places where they'll rub together and create bonafide itching powder. Kevlar won't itch, nylon, etc.

[Leon01323]

Yer may get some dust but that will be fine, will loose it on the hill wish I could afford Kevlar.

What do you guys reckon I should make the deck out of? Regular Matt is gunn take so many layers. Was thinking of using cloth as i think it will be better but I've heard it does not bond well in layers? But have seen decks made out of it.

Thanks guys