who here does fiberglass boxes????HELP!please

Post by **kg1961** » Fri Feb 13, 2009 8:58 am

I have a question I bought one made for my car and were the front of the box meets the back there is a large crack in the fiber glass
how wood I fix it? there is bond to makr the box smooth.
my question is do I sand it down to glass again to repair or can I just go over it?
here is a quick picture
http://s235.photobucket.com/albums/ee143/lyckam/

Post by **stipud** » Fri Feb 13, 2009 9:10 am

Hmmm that sucks....

On the inside, sand down any bondo (shouldn't be any), lay down some chop mat and coat it with resin. Should be good to go after a few layers.

Odds are if it's cracked like that you should do a lot more reinforcing on the inside to make sure it doesn't happen again.

Post by **kg1961** » Fri Feb 13, 2009 9:14 am

I here that! I think the guy also just used paper to put in the box so it got dropped like 100 times coming from florida. nice glad I got it for one hell of a deal but...
Off to crappy tire tonight

Post by **smgreen20** » Fri Feb 13, 2009 9:42 am

Make sure you leave a rough surface after you've grinded some of it down so that when you put the new glassed mat in it has something to "grab" to for a better bond.

Post by **kg1961** » Fri Feb 13, 2009 10:00 am

thanks for the pointer anyone else

bretti_kivi · Post by **bretti_kivi** » Fri Feb 13, 2009 11:07 am

drill holes if you have to.
Polyester resin is easy to mix "hot" (a little too much hardener) , with epoxy DON'T DO IT! Epoxy takes 24h to set, polyester max a couple hours.

Make sure the room is warm and not too humid; polyester stinks.

Bret

gridracer · Post by **gridracer** » Fri Feb 13, 2009 12:59 pm

I work on fiberglass alot here is what I would do.
1st. on the inside of the box sand the area where the crack with a coarse sandpaper to get a good bond.
2nd. get all the dust out use a automotive reducer to wipe it clean.
3rd. get some fiberglass chop mat and resin and do a few layers over the spot where the crack is brushing it on and tapping it so you have no air bubbles. you should SAND BETWEEN each cost of resin and removing dust. I would maybe look over the rest of the box to see how strong it is and add chop mat in other areas if you think it needs it. You only want to have to do this once so get it all good now.
4th.For the outside of the box sand down the area around the crack to give you a good area to fill with a coarse paper and there willl be filler cause its pretty much impossible to get resin smooth enough for a painted smooth surface.
5th get yourself some evercoat kittyhair fiberglass reinforced filler(strongest) (stay away from bondo brand if possible) or some evercoat rage gold easiest to sand and spread it over the area where needed sand remove dust and repeat until you have it smooth again you can use some spot putty filler for small pinholes it sands easy.
By doing it this way you will save yourself a ton of hard sanding its alot easier to sand down filler than chopmat and resin thats why you put that inside so it doesn't need to look good. Plus if you did chopmat on top you change the shape of your enclosure.
Anyway questions ask

bretti_kivi · Post by **bretti_kivi** » Fri Feb 13, 2009 1:09 pm

^^ that sounds like excellent advice. Trying to lose the bubbles is essential.

Bret

Post by **ttocs** » Fri Feb 13, 2009 2:30 pm

looking at the pic it doesn't look like it is cracked completely, just a large scratch in the primer? If that is the case and you just want to smooth it out, just get some bondo and fill in the scratch.

Post by **kg1961** » Fri Feb 13, 2009 2:42 pm

nope its all the way through and 26inches long that doesn't show it all but I can see the floor when I look in it

gridracer · Post by **gridracer** » Fri Feb 13, 2009 2:43 pm

ttocs wrote:looking at the pic it doesn't look like it is cracked completely, just a large scratch in the primer? If that is the case and you just want to smooth it out, just get some bondo and fill in the scratch.

Your kidding right ? you can't tell thats a crack?

Thumper88 · Post by **Thumper88** » Fri Feb 13, 2009 2:56 pm

one hell of a crack at that.

Grim0013 · Post by **Grim0013** » Fri Feb 13, 2009 4:49 pm

Who was the shipper, and was it insured? I think UPS has like, $100 of insurance for "free" on any shipment. Not sure about others. May be worth checking out.

As to the repair, gridracer gave sound advice. If you use a resin that does not have wax in it, you shouldn't need to sand between coats.

The stuff they sell at home depot is generally shit. A boat store will likely have more/better fiberglass selection. A dedicated fiberglass supplier would be best. I use http://www.fiberglasssite.com They have good products from what I can tell, a wide selection, and some really good tutorials. The downside being that I don't think they sell in very small quantity. You'd probably need to get enough to build a whole enclosure. Though it would likely cost only a little more than what you'd spend at the home depot on a smaller amount of lower quality materials.

BTW, I am new to fiberglass, so take my advice for what little it is worth.

Post by **ttocs** » Fri Feb 13, 2009 6:17 pm

it shouldn't be too hard to repair if you need to. Put some tape on the inside of it alont the crack to hold the resin in place and pour it and some resin and chop-matt. As they said keep the bubbles out of it and with some sanding and paint you should be able to fix it.

I would do that after looking into the shipping insurance. They normally deny everything and if he didn't pack it right then there is no chance. IF you used paypal you can file a dispute.

Post by **kg1961** » Fri Feb 13, 2009 7:23 pm

Im trying right now but even if I go to file the claim I still need the box the new one is over 500 us shipped I paid 150us shipped so really $50cnd and 5 hours work shit can't lose in my mind and I was going to cover the box with leather viynl or carpat so not to worried maybe carbon fiber cloth?? I don't know spent One hour sanding the out side itchey as hell now so Im done tonight
I like the idea of using tape than add resson than add the matting on top shit I can have that done by monday if thats my game plan
any cons to doing it that way????

Post by **kg1961** » Fri Feb 13, 2009 7:23 pm

Im trying right now but even if I go to file the claim I still need the box the new one is over 500 us shipped I paid 150us shipped so really $50cnd and 5 hours work shit can't lose in my mind and I was going to cover the box with leather viynl or carpat so not to worried maybe carbon fiber cloth?? I don't know spent One hour sanding the out side itchey as hell now so Im done tonight
I like the idea of using tape than add resson than add the matting on top shit I can have that done by monday if thats my game plan
any cons to doing it that way????

Half-Fast · Post by **Half-Fast** » Fri Feb 13, 2009 8:44 pm

From my experience, UPS will claim inadequate packing and won't pay.

bretti_kivi · Post by **bretti_kivi** » Sat Feb 14, 2009 1:27 am

... don't sand that stuff inside if you can avoid it; use water if you must or a dust system (think vacuum cleaner if needs must!) and USE A RESPIRATOR! 3M has some cheap ones - $20 or so - and they are a damned good idea.

Bret

gkitching · Post by **gkitching** » Sat Feb 14, 2009 3:00 am

gridracer wrote:I work on fiberglass alot here is what I would do.
1st. on the inside of the box sand the area where the crack with a coarse sandpaper to get a good bond.
2nd. get all the dust out use a automotive reducer to wipe it clean.
3rd. get some fiberglass chop mat and resin and do a few layers over the spot where the crack is brushing it on not tapping it so you have no air bubbles. you should SAND BETWEEN each cost of resin and removing dust. I would maybe look over the rest of the box to see how strong it is and add chop mat in other areas if you think it needs it. You only want to have to do this once so get it all good now.
4th.For the outside of the box sand down the area around the crack to give you a good area to fill with a coarse paper and there willl be filler cause its pretty much impossible to get resin smooth enough for a painted smooth surface.
5th get yourself some evercoat kittyhair fiberglass reinforced filler(strongest) (stay away from bondo brand if possible) or some evercoat rage gold easiest to sand and spread it over the area where needed sand remove dust and repeat until you have it smooth again you can use some spot putty filler for small pinholes it sands easy.
By doing it this way you will save yourself a ton of hard sanding its alot easier to sand down filler than chopmat and resin thats why you put that inside so it doesn't need to look good. Plus if you did chopmat on top you change the shape of your enclosure.
Anyway questions ask

Good advise here.

One tip I could add would be to tape off the FRONT. All the way around the crack. That way no resin will seep out while repairing from the inside. Once the resin is hardened, remove the tape and the gap should be filled perfectly with little bondo'ing or surfacing required afterward.

Unfortunately, by the looks of that crack, it doesn't appear there is any fiberglass mat used. Like it was done with just fleece and not reinforced with mat. If so, you will need to add matting or that won't be the last crack.

wash with gasoline · Post by **wash with gasoline** » Sat Feb 14, 2009 5:27 am

lots of good advise so far. what i would do is sand the inside around the crack with some ruff sandpaper, make sure u get threw any base coat or paint if there is any. vacum out the dust, wipe it down with acetone.tape over the crack on the outside. cut as much matt as u want to use (at least 3 strips if it was me) and lay it in place inside dry to figure out how it is going to fit, much easyer to trim and plan before you have resin kicking off. once you have it mapped out in your head take it out an lay the matt on a piece of cardboard. put on a fresh set of gloves an make sure you have good ventalation, mix up your resin and use a cheap paint brush to spread the resin on both sides of the matt till its soaked all the way threw, paint resin on the inside of the box all around the crack, lay down your matt in the box and roll out the air with a roller if one will fit, if not you can use your fingers to push out the air, just like you would with a sticker. make sure you smooth out the edges of the matt before you leave it to kick off (its a pain to have to sand it smooth later) remove the tape after the resin has kicked off about halfway so you can clean up any that soaked threw with a acetone rag instead of haveing to sand it off later. if you have any leftover mixed resin when you are done paint it on some skrap or cardboard, if you leave it to kick off in the bucket you mixed it in it will get really hot an can cause a fire. after its all kicked off fill up any of the crack left with putty or bondo and cover leather or viynl like you wanted. and if there isnt any matt in the whole box you are going to want to put a few layers on the whole thing. IF YOU DONT HAVE GOOD VENTALATION DONT DO IT, even if you have a resperator that is good for the resin you use, the stuff will get into you threw your tear ducts an eye balls. ...sorry bout the long post, its late an i cant sleep

Post by **ttocs** » Sat Feb 14, 2009 7:39 am

I really think you will have problems trying to seal that crack with a solid piece of matt and no air bubbles from the outside. You can tear the matt up or chop it up and just try to put as much resin and material in the crach as you can.If you suspect that it might be a little thin then why not just put a new layer across the entire inside once it is done. This will ensure it is sealed and also help to fill and other small cracks that you can't see while giving it added strength.

Vinyl and CF will show EVERY little defect in the box if it is not absolutely PERFECT. Carpet on the hand can hide alot......

Also get some gloves to use when the resin is hot. Make sure they are powder free and you will be fine. Make sure you have EVERYTHING you need from gloves to brushes in arms reach, you have your phone off and the dog inside before you mix your resin. I can't tell you how many times just after I mix it I realize I have forgotten something important, or the dog comes up and wants some attention........

Post by **kg1961** » Sat Feb 14, 2009 7:51 am

no problem guy I think I got it
I have the glove , all the tool
there is one layer of fiberglass but it cracked on the edge almost all the way around
I here ya witht eh phone off dog and cat out of the way beer open.. just kidding
I will go get a cheap paint brush tonight after work
the reason it goesn't look like fiberglass on the front is it was bondo prime and preped
with a little luck I should be done by monday
thanks again
Mike

Post by **ttocs** » Sat Feb 14, 2009 9:02 am

I think I would start on the inside to be honest. Put a complete layer inside and then work your way out. Also make sure to mask off any areas that you do not want the glass on as it is easier to peel the tape off then to sand it off.

I normally just get the cheapest brushes I can and throw them away after each use. Harbor freight has the best prices around me.

gridracer · Post by **gridracer** » Sun Feb 15, 2009 1:42 am

wash with gasoline wrote: if you leave it to kick off in the bucket you mixed it in it will get really hot an can cause a fire.

In the 20 years i have been doing fiberglass work for people and the shop I worked at I have never seen or heard of that happening even when we mixed a hot batch (extra hardener) it never happened. I've left cupfuls of extra resin on the work bench many times. It will melt styrofoam cups but only a moron would use styrofoam. Big gulp cups are about the thinnest plastic cups there are and no fires.

bretti_kivi · Post by **bretti_kivi** » Sun Feb 15, 2009 1:54 am

I've had some smoke on me.... that was kinda interesting.
I was v. happy it was snowing at the time, out it went...

Bret

who here does fiberglass boxes????HELP!please

who here does fiberglass boxes????HELP!please

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