HI If you type (homemade vacuum pump) into google you should get some links to make your own. I made one from a wall aircon compresser and it works fine . Buying a vacuum setup seems a bit over the top to me as I have repaired a couple of boards and don,t bother trying to use a vacuum setup on a nose repair. Good luck.
I have cracked the nose down both sides and was going to glass the nose area with a some carbon/kevlar cloth to beef it up a bit.
It doesn't need any core material added, i was just going to sand back and patch over the whole area. Does this mean i don't have to bag it?
I have done plenty of polyester board repairs over the years but this is my first go at a modern epoxy board.
I have got a fridge compressor and was keen to get into building a diy one, but was getting worried i would not have my board fixed by the start of my season, (which is when i send the kids away to their grandparents for a holiday)
The main need of vacuum is to clamp the high density core material to the core, while the resin goes off. It can also be used on the final cloth layers to squeeze out excess resin, giving a high fibre to resin ratio.
Your repair doesn't really need either of these.
Carbon kevlar is a great idea, but remember the kevlar is almost impossible to sand. A vacuum bag can help here, keeping the lay up flat. But you can achieve a similar affect, with plastic stretched over the rails with tape, or sandbags on horizontal surfaces. I usually include a sacrificial layer of fibreglass over the top as well. If you do sand into the kevlar and it goes furry, shave the fur of with a very sharp blade, and spray over with a thinned out paint, when the thinner evaporates it sucks the fibres down, a series of light sands, shaves and sprays will eventually get rid of the fur. Unless you get too enthusiastic with the sand paper.
People have tried it and ended up buying a new cleaner. Unless you maintain airflow thru the cleaner it overheats and burns out. It's possible I guess, if you can just use some sort of bypass and still get enough vacuum. But I haven't heard any success stories.
You might not need the pump for this job but if you have a fridge compressor already you may as well make one. I made one recently using 555s great article www.seabreeze.com.au/Articles/Windsurfing/How-to-build-your-own-vacuum-pump-for-under-50_1293413.aspx I'm yet to use it for a repair but testing seems to work fine. I used a vacuum advance from a HK Holden distributor for the pressure switch and it only drops to 8"hg so doesn't even need the spring adjuster dealy.
On a related tangent, what is the right type of plastic to use which wont stick to epoxy?
Thanks everyone for your advice, looks like there is nothing stopping me getting started this week, i will go for a sacrificial layer of glass over the top of the kevlar to make tidying up a bit easier.
Decrepit I loved that board building thread you had up on seabreeze a couple of years ago, I would love to build a board one day. That big slalom/freeride board that mr love had built looks the bomb!
I already have Australia's ugliest looking example of go155, after the previous owner peeled all the stickers off the front of it, it's now about to get uglier!
• Will put vacuum pump on the to do list • Have beer kit ready to go, but can't find my immersion heater since moving house.
Be aware that an off the shelf vacuum pump will just pump it's little heart out and turn your board into a very flat thing unless you add in either a bleeder valve, or some kind of vacuum / pressure switch.
I've heard nasty stories about "stuff" getting stuck in a bleeder valve and preventing it bleeding while the operator was out of the shed, so I opted for a vacuum switch on my setup.
I recommend the fridge pump system because it's cheap and it's quiet. I borrowed one of those other sort for a while on a big job, and ended up wearing earmuffs. Not the sort of machine to leave running overnight if you plan to sleep anywhere near it.
If you set up your bag properly the thing should only cycle very infrequently, so a constantly running pump is major overkill.
Put it on your to do list (you really don't need one for this job). Get familiar with the parts you'll need, and you'll probably find that they just seem to turn up before you get around to actually doing it.
Thanks to you other guys for the comments on my article - it's really good to hear that someone has gotten some use out of it.
i worked in boat yard for 1 year ... in my opion it wouldnt be nessesary to vacume bag a simple nose repair ...... just use some peel ply cloth to smooth the resin and cloth .... depending on the size and if the cracks are water proff .. sand the cracks to creater a larger surface area and just drible resin into the crack
if you have water in the board then vacumming it for a while first before laying up any glass may help dry it out. You will probably get a better repair using a vacumm pump and bag but a small repair should be prefectly adequate without bagging. using peel ply will help soak up excess resin and give you a fairer finish that is easier to sand.
What is peel ply? i haven't heard of it before, could i get it from my local fiberglass shop? Thanks to everyone for their replies i am really looking forward to starting the repair this week.
peel ply is actually rayon fabric which you lay down on top of your actual laminates ( glass, carbon, kevlar, etc). It soaks up some of the epoxy resin from the laminates ( which is a good thing). after the resin cures you peel off the peel ply and you are left with a matte, textured finish that is easier to sand than the gloss finish you get without peel ply. if you don't mind using a bit of material you can even lay peel ply on epoxy filler to make it easier to sand.
most fibreglass suppliers will sell peel ply or you can buy rayon jacket lining material from spotlight. you may want to do a test piece if you buy the material from spotlight cos sometimes you don't get what you think you do when buying material. however, i know some very professional boatbuilders who build exotic yachts that get their peel ply from spotlight.
You only get the full benefit from peel ply when pressure is applied. I don't think it "soaks" up resin, but it does wet out fairly easily. Pressure applied to a layer of cheap quilting wadding over the top of the peel ply will flatten the cloth and squeeze out excess resin. The easiest way to apply this pressure is with vacuum, but it can be done in small areas with weights or on the rails with masking tape.
If anything does "soak" up resin, ie wicking or capillary effect, your going to end up with pit holes that have to be filled again. When I first tried vacuuming the outer glass layer I used some scrap fibreglass over the peel ply, this does soak up resin and left a very dry finish. If in doubt test the material by draping over a container of water, half in the water and the other half hanging on the outside lower than the inside. Something that soaks well will eventually empty the container, don't use it!!!!! Something that doesn't soak will only be wet where it's been submerged, this is the stuff to use. That way the only resin you loose is the amount that's squeezed out.
Interesting about the rayon, I tried something from spotlight that looked right, but it didn't release. When I enquired (forget who from) I was told peelply is covered with a release agent, and other stuff doesn't work. But now I'm going to have another try!
decrepit, some rayon jacket lining material works and some doesn't. i've some good mates that have built large carbon sportsboats and cats using this stuff. The stuff from FGI is good though because the red pin stripe in it makes it easier to get it even and bubble free.
while i agree that a vacuum will produce a stronger and lighter structural repair I still reckon that you will do the repair easier and get a fairer result using peel ply when compared to not using peel ply. When you do a laminate without vacuum or peel ply the very outter layer of resin doesn't really cure 100% and remainds kind of waxy. this is why when you sand it it clogs your sandpaper very quickly at first. using peel ply avoids this. Additionally, the textured surface is so much easier to sand itself and you can very quickly see high and low spots during fairing. Also, peel ply allows you squeegee the laminates pretty hard, consolidating the laminates and removing voids.
OK, that does make sense, could have used that trick over the K12 carbon, that really needs a lot of squeegee work to wet it out. But I don't have trouble with the outside film of resin not going off. I'm using botekote and it doesn't bloom. It can clog the sandpaper if it's sanded too early thou.
A red stripe sounds great, I normally draw a centre line on the peel ply, (put it on the board dry first), for the same reason.
