Fibreglass and other advice needed

[Niroth]

So the story goes:

I'm a member of nissanexa.com. One of the members so graciously organised a group buy of vented fibreglass bonnets from Topstage in Melbourne. A one man show body kit manufaturer. Long story short it took 3 goes to get the bonnet here as closed to finished as it will ever be.

Just a note on Topstage: If anyone has ever heard of these guys, or is considering buying something from him, DONT!.

Ok, now down to the crux of my problem. The bonnet isn't terribly well made. It was supposed to have a gelcoat on it as a finish but I dont think it has. The finish is extremley average, scratched, not smooth etc, and I want to fix it. I'm considering my options and have come to the conclusion that re fibreglassing the top of the bonnet is the best way to go. I've found that bunnings here have "diggers" brand resin, hardener and figreglass weave sheeting. Anyone used this brand of fibreglass stuff? Good or bad?

I will have to prep the surface of course, thats no worries. I will be painting the bonnet anyway, so I'm wondering if I should just paint a good 4 or 5 layer of resin onto the bonnet surface, to add a smooth surface and to add a little extra strength, or if I should actually add layers of fibre to the top as well as the resin.

The other think I want to look at doing, is properly re-enforcing the underneath of the bonnet. I'm contemplating using small aluminium angle iron underneath, in basically a W shape, and attaching plates to the "start and end" of the W which will go between the bolts and the bonnt itself, to secure the W into place. Ideas? will it work ot not? Basically when the bonnet is up and sitting on the arm that holds it up, the other side of the bonnet sags down because there is no rigidity to the whole thing.

Any suggestions would be good, especially on the fibreglassing issue.

Jase

[racsov500]

when you do it, make sure you wear long sleeves pants ect, unless you want to be itchy. a mask is always a good idea too

what a dodgy company (if it is) make sure they know about it

[blacky]

its a hard call - just resin over the top will be very brittle and probably wont be terribly strong. Other hand, laying some weave mat onto it probably wouldnt give the best finish.

Ive glassed up broken bodykits before, and I got a paintable/smooth finish by mixing resin, talc powder and chopped fibre strands, then dobbing that onto the holes. Once hardened, i sanded that back smooth and it was perfect. I dont think this is an option for you though or if its even relevant but i hope it helps anyway. best of luck btw, fibreglassing is lots of fun

blacky

[Dee 33]

Resin under your fingernails is lots of fun too

But yeh, I wouldn't resin the top of the bonnet and it will be brittle and will probably crack. And I wouldn't lay weave down either because that will look a bit shitty. Any reinforcing you do should be done from the underside so flaws won't be seen.

I have used the stuff from Bunnings for my bodykit. It was pretty average. My mate had a LOT more success with a repair kit for surfboards as the resin at this stage is a lot more mouldable where the bunnings stuff is like working with estapol until all of a sudden it turns to jelly then goes rock hard within 1 minute.

[memphis]

fibreglass bonnets are made in 2 parts, then sandwiched together to form 1 solid part. alot of fibreglass bonnets sag because of this, angle might work, but only if its installed correctly

regarding reglassing it: if theres no physical damage to the bonnet and the glass seems fairly sturdy, maybe you could just skim it with fine layer bog to fill the deep scratches and then use a putty primer to smooth and finish it. (basic practice with most fibreglass bonnets to fill all the imperfections, fibreglass rarely comes out of the mould with a perfect gelcoat)

[Niroth]

Yeah, I had a suspicion that the resin coat on the top might crack.. I'm not 100% sure what to do. There are areas on the bonnet that definatley need more fibreglass and resin, I mean parts that are so thin you can actually see thru them. There aren't really too many deep scratches in the top of it. I don't know if this bonnet has been made in 2 parts. I think he's made a mould and just laid all the fibreglass and resin in there and left it to cure. I dont think the bonnet is actually thick enough, even a light touch on the top and the bonnet can be easily pressed in in certain areas. I wonder if I would get a better result cutting off what little reo there is and completley reglassing the bottom.

You said that you wouldn't lay weave down on the top, but I am not relaly sure why??

I figured laying a few layers of woven and a good amount of resin would not only make it a little thicker, but give it a more even surface. The bonnet is going to be sprayed anyway, so in the case of laying weave and resin, and another 2 coats of resin, wouldnt that mean that there isn't too uch resin to cause it to crack, but enough to give it a harder surface to paint?

I've tried to find the surfboard resin stuff round here but I just cant get it, and I cant see anywhere on the net to buy it in australia. The CSM sheet that comes with the bunnings kit isn't what I'm planning on using. I've found some proper weave that I'm gunna use. From everything I've read, putting one or more layers of weave on top is going to be the best idea in regards to strengthening, because it will be high strength up and down, as well as side to side, which (in my head) would mean less chance of twist.

Jase

[memphis]

do not put glass on the top, if you are going to do any glassing, do it from beneath.

it will be impossible for you to smooth it out properly if it is on the top

[Niroth]

Is there anything I can put on the top to give it a proper surface for painting? I've been told bog s a pretty dodgy way of going about it, but I'm open to options.

Jase

[tikki169]

do not put glass on the top, if you are going to do any glassing, do it from beneath.

it will be impossible for you to smooth it out properly if it is on the top

I'm with you on that. I usse to own my own business back In south africa making and supplying fiberglass kits adn I've done hundreds of hours of laminating.

Never put glass on from the top always from beneath. It'll take you hours to try level and smooth it out again. If you want to put anything ontop go to a proper fiberglass supplier and get sandable gelcoat. That way you can fix up the areas and sand it back. sandable gelcoat is still rigit but flexable enough not to crack. On that note you can still bog it up with body filler depending on how bad it is. Unless I can see the bonnetr I can't give you an exact proceedure but my best bet is the SG, as it sands down to a smooth finish.

[FATGTS-R]

If you have taken it back 3 times and still obviously unhappy with the result why not ask for your money back? Or keep taking it back again and again and again till its right or he gets fed up and gives your money back anyway.

You said it was part of a group buy, so how did others peoples bonnets come out?

[Niroth]

This guy is actually a uni student and the money is gone. Other peoples standards are lower than mine. I have asked them about the finish and other little things I noticed about mine and they have the same low quality units. Onle woman is taking him to small claims court about it. I like the bonnet shape and everything, but sending it back the first 2 times has proven to be basically useless. This guy obviously does not have the knowhow on making fibreglass products, at least not to a prefessional standard.

Well it seems to be the going suggestion that nothing gets put on the top. I don't need to "fill" the top as such, but it cant be polished, I've tried. The finish is basically shit. So this gel coat, can someone explain exactly what it is? Is it a paint, or resin or what? Does it have any viscosity to be filling flat spots? this flat spot that I'm talking about seems to be just where its sagged. its maybe a 5mm drop in the centre and about a foot in diameter. I figured I would just need to to use a little more resin in that area to just level it up, can the gelcoat do this? What prep is needed for the gelcoat, a light sand and wipe down with acetone would be sufficient I'd think, but is there any other prep or coating that has to go down first?

I'll re-enforce everything from underneath as suggested. Being right above the monitor, do I have to be carefull about heat and using too much resin? There are some specific areas that might be a little hard to get the glass into, but I dont want to do it, only to find it doesn't bond properly.

The other thing about glassing underneath.. the underneath of it is basically CMS glass, its all rough as if there hasn't been enough resin put on it. Am I going to have to do anything to prepare that to have new glass and resin put on it?

Jase

[tikki169]

Don't put acertone on it. Acertone disolves resin so that's a big no no.

OK gel coat is a resin...sort of. You use it as the first layer in a pruduct. GC is either brushable or sprayable, I use brushable cause it's thicker. It was viscosity but not incredibly much....kind of like a syrup viscosity to it. For a 5mm repair yopu can paint on a layer...let it dry and then paint on another layer. What you need to do to prep it is just was it with warm soapy water(to make sure any wax and releasing agent is removed) then a light sand with about 180 paper just sto roughin it up. GC doesn't stick well to smooth surfaces. If you can get ahold of sandable (brushable) GC then it's going to be alot easier cause tooling GC id F***ing hard (I use this to make the moulds) and you'll sand your butt off.

Any reason that you don't want you use body filler. BF is flexible aswell and alot less work.

Um underneath you can just roughen it up with some 80grit paper (aftre washing) and paint resin on. It sounds like he's used to heavier matting (matting comes in dif weights per square meter and the heavier it is the more dense it is so needs more resin) if you use heavy matting and lnot enough resin you get that horrid rough finish. Instead of using say 2 layers of 450 I'de use 1 layer 300 and 1 layer 450 and just use a bit more resin for a better finish.

Any further help just drop me a PM and I'll try help if you like.

[Niroth]

Ok, THis brushable (and sandable) gelcoat sounds like exactly what I'm after. A 5mm coating over the top is just about right, and it seems gelcoat is 100% UV stable and good for painting on. As for the bottom, I dont know what weight CSM I have, but should I use cms or weave? the bottom of it looks like shit, you can see the CSM and in places actually pull strands off. For the tighter crevases where there is so little resin I can see through it, whats best there, just cut up a few really thin strips of csm to put in the bottom of the V kinda shape, or just fill it with some resin?

Someone commented about using de-greaser on the bonnet to remove all the grease and wax, what sort of effect will that have on the surface of the bonet? With regards to the viscosity of the brushable gelcat, will it hold to an angled surface, or is it too thin and will just kinda run down to the lowest level.

Last question for this post, where exactly would I find brushable, sandable gelcoat?

Oh, and no one told me if there were any problems with the resin so close to heat, does resin have a expand and contract property at all? will being under such high heat cause me any problems? do I have to make any special considerations when selecting a paint (for the underside) and if so, are all paints equal. I dont want to put something on there that will cause me headaches in the future.

Thanks heaps for all your help guys, keep it coming.

Jase

[blacky]

just a side note, would be an awesome experience to mould out a Skyline bonnet, then run off fibreglass copies... would be great for intakes, scoops, replacements. And fibreglassing is fun too!!

blacky

[pinoi_boi_r33]

this is the first time i've heard of some thing bad about topstage. he is very respected on www.nissansilvia.com , its such a shame best of luck.

[xr8eater]

if you want a smoth finish on the top of the bonnet it is definatley going to have to be high build its like a thick paint that is easly sanded with wet and dry sand paper this will remove the scraches and stone chips. gell coat isn't for beginers and shouldent be brushed on the same goes for high build hope that helps.

[tikki169]

Admittedly GC isn't for beginners but it can be brushed on, that's why they sell Brushable GC, it's thicker than sprayable GC. I've always used Brushable and have made thousands of products. I'm busy making a copy of mirrors and an airbox/heatsheild for 32's and I'm using brushable.

GC is pritty thick and depends on the angle you're applying it to. If you're gonna apply it to something vertical then yeah it'll run but if it's just at a slight angle the run will be minimal. It's pretty thick stuff.

I woulodn't use degreasa. It won't affect the fiber but it'll make it tricky to paint as some of the additives in it are reactive with paint and you'll get fish eye (this is the same effect you'll get if you spray silicone and try to spray over the top) paint wont hold to it in places.

[predator]

Don't go to bunnings, go to a boat supplies shop.. they should be able to advise you on a few things, and will have a large range of fibreglass products that are more suitable for the job.

[xr8eater]

true gel coat can be brushed on but i dont like sanding for hours to get the brush marks out

[SirSkyline]

Is there anything I can put on the top to give it a proper surface for painting? I've been told bog s a pretty dodgy way of going about it, but I'm open to options.

Jase

Probably the safest way would be to 2 pack polyester it then 2 pack primer over the top. The polyester is pretty much a bog but in spray-able form and the 2 pack primer is to finish it off and fill anything you missed. The poly will fill large scratches and dents within reason. Use Standox or Dupont paint products and you wont go wrong