Help, need a fibreglass patch

[Hanne]

Has anybody a small patch of fibreglass and some resin, need to put a patch on the back of a panel which has a crack to keep it strong.
Just a small patch (maybe 3x3 inches), so I didn't really think it was worth going to a shop for.
Has anybody got any spare bits left over?

Thanks,
Hanne
:sunny:

[Drum]

I've got the fabric and resin+hardener, but cant send the chemicals in the post. If someone in Auckland has got the resin I can send you the fabric patch.

[slopster]

Fabric costs fuck all like $5 for a square metre at the boat shops. I think resin is about $20-30 for a small tin

[JeremyW]

We do a bit of carbon and fibreglass. Give me a call tueaday and we can sort something out.

Jeremy 0272957769

[Squiggles]

found some in the shed that came with a surfboard the olds bought, hopefully we patched it right, curing now :yes:

thanks anyway guys, we'll be in touch if it did go wrong! :shutup:

[Hanne]

Thanks for the replies guys,
Still wasn't dry after 5 nights in a reasonably waarm shed os we have pulled off what we did (peeled, really) and I think I will start all over again, probably with some fresh resin (eould the age of the chemicals make a difference?)
(How long should it generally take for fibreglassing ot dry? Not 5 days, right??)
Thanks!
hanne

[imdying]

Needs to be about 20 degree minimum for best results, the colder it is, the longer to cure. Ratio of hardener to resin is pretty imortant, you can't just add more hardener to speed it up.

[Drum]

Last time I did some, it set pretty hard overnight.

Should be an expiry date on the container too.

[Hanne]

Yes, the chemicals were pretty old! We measured out the ratios according to the label, but it didn't set properly (15-20 degrees in the back shed, heaps of warmth from all the fish tank pumps!)

[imdying]

Bummer, have to try some fresh resin then.

[IamCornholio]

Thanks for the replies guys,
Still wasn't dry after 5 nights in a reasonably waarm shed os we have pulled off what we did (peeled, really) and I think I will start all over again, probably with some fresh resin (eould the age of the chemicals make a difference?)
(How long should it generally take for fibreglassing ot dry? Not 5 days, right??)
Thanks!
hanne

I would think that the age of the chemicals would not matter as much as the ratio of hardener to resin and the temperature you are applying it under... :scooter:

Fiberglass resin (polyester resin) is basically the same as what's in Bondo. In pure form it is like water, but usually the stuff we see is like syrup because it is thickened to make it easier to handle. The same basic ingredient (MEK peroxide) is used as a catalyst in Bondo and fiberglass resin. Mixing the correct ratio of liquid hardener to liquid resin is difficult and you need practice and experience. Temperature is extremely important. Below 64 degrees Fahrenheit the resin won't cure properly with the correct ratio of hardener. You can add a little extra hardener but too much and it cures unevenly and can trap gasses and styrene in the part or crystallize the resin and make it brittle. Over 95 degrees Fahrenheit it cures real fast and thicker areas can easily cure too hot and crystallize. It starts crystallizing over 140 degrees Fahrenheit. It's best if you can work between 75 and 85 degrees Fahrenheit (the temperature of the mold or part), and maintain some air flow and the correct hardener ratio, for a nice slow even cure. :yes:

The hardener MEK peroxide is a catalyst that produces heat in the resin. It needs to be at 64 degrees Fahrenheit minimum to cure, and the best is between 72 and 80 degrees Fahrenheit. At times I will use heat lamps to help 'speed' things up for me... :innocent:

The temperature is directly proportional to the amount of hardener and it just takes time to get it dialed-in. Also always mix the batch as thoroughly as possible...

Different companies thicken their resin in different ratios, which proportionately affects the hardener ratio. It takes years of experience and knowledge to get real good at this, and I tend to screw up lot of parts when I get in a hurry and do not use the correct amount... :innocent:

Hope this helped you out some Hanne, I was trying... :cool:




IamCornholio (Lord of the Harvest - Master of the Worm)

[Hanne]

Thanks for that IamCornholio, obviously there are a lot of things to balance up!
(I did do chemistry at High School but actually managed to set the floor of the science lab on fire with a flaming marshmallow.... ><)

[IamCornholio]

Thanks for that IamCornholio, obviously there are a lot of things to balance up!
(I did do chemistry at High School but actually managed to set the floor of the science lab on fire with a flaming marshmallow.... ><)


I had a couple of cracks in our lower cowl and used some fiberglass cloth and resin to fix them just like you described in the beginning of your thread... :yes:

Also like you, I followed the directions on the can for mixing the hardener and resin and it was NOT working for me. (In my case the stuff was getting hard in minutes using the 'Bondo' brand suggested 12 drops of hardener to 1 ounce of resin) :shit:

I saved myself from wasting a bunch of resin by getting the 'mix' worked out by testing one ounce at a time until I got it right for our temp and the speed that I wanted to be able to work at. I ended up at about 8 or 9 drops per ounce BTW... :scooter:

I bought an aftermarket pipe for our bike that 'needed' to come through the side of the lower cowl a bit because it was so big and I HAD to make the plastic strong enough to cut on it without it cracking to bits. 5 thin layers of fiberglass cloth did the trick for me and our stock plastics are now 'bulletproof' and I am able to cut and drill all the holes in them I want with no worries. :Punk:

Glad some of this stuff helped you out Hanne. I appreciate you guys having me here at KB. Glad to be a member for sure friend! :yes:


IamCornholio

[lordandrevv]

the age of the chemicals does matter, but the ratio of hardner to resin is more important. The recomended ration is 1.5 - 3% depending on temperature, the normal is about 2%. And yes heaters do reduce the curing time, however you don't want the reaction to happen to quickly as the resin will warm up to much and can crack and ruin the whole job...thats why its important to not apply to many layers at a time...

[imdying]

Thanks for adding to the thread mate, bling for you :yes:

[Indiana_Jones]

I have a crack in my fairing over a screw hole i'd like to fix before it gets any bigger.

Can anyone here point me in the right direction for someone that can help for a small patch up on the back, just so it's strong (don't really care about the cosmatics that much)

Cheers

-Indy

[lordandrevv]

I have a crack in my fairing over a screw hole i'd like to fix before it gets any bigger.

Can anyone here point me in the right direction for someone that can help for a small patch up on the back, just so it's strong (don't really care about the cosmatics that much)

Cheers

-Indy
if you have the factory panels (I'm guessing the bike is CBR250R) they are made out of plastic. Take it to a plastic welder and get him to fix it up. Should be quite cheap. You could fix it with fibreglass, but it would mostly be a bit of epoxy resin that would be acting as glue. Unless you got a hole to fill, i recommend plastic weling. (i work in a fibreglassing shop :-P)
Andrei

[Indiana_Jones]

Yea, they're the factory ones, well one of the side ones in (I think the one with the crack is factory)

How much do you think it'd be for welding?

-Indy

[westie]

If anyone needs repairs done with fibreglass or are making new panels and need a hand. I have all the appropriate materials, tools, experience to lend a hand.
Yep thats what it sounds like:tugger:

but really, more than happy to help out with the itchy stuff(fibreglass).

[lordandrevv]

youp
same here with fibreglass. I might not have a huge amount of experience, but definatley more than most people as i work with it every day.
I'm happy to help if anyone needs it.

Oh, btw indy: If its one crack (say 5cm long) probably no more than $20-30 surely. Even cheaper if you clean up the welds yourself afterwards. Plastic welding is cheap