Fiberglass/gelcoat

[kluth]

I have done NO work on fiberglass/gelcoat finishes. I am refinishing a hood and am seeking guidance. The hood is in good shape, but has some spider-webbing and small scratches. What do I need to do to acquire a smooth surface prior to paint? Any "special" requirements for final sanding, etc. or is it similar to working with metal?

Kirk

[racingelvis]

kirk, "if" the cracks are not terrible and are just normal spider cracks, you can sand just the areas or the entire hood with a 180 grit. buy some polyester filler and spray either the cracked areas ware sanded or the whole hood if sanded. the polyester is that thick it will fill the cracks just fine. then block sand the hood with 180 grit flat. after the hood is sanded go over the entire hood with 320 grit to help feather edge the 180 grit scratch. then you have to spray a urathane 2k primer over the entire hood. after that dries wet block sand entire hood with 400 grit, after entire hood is sanded go back over with 600 wet paper just folded in your hand. that will help feather edge the 400 grit scratch out. after that blow dry, seal and paint. in a nut shel this is what we do. call me if you have any questions and i will be glad to help you out and i can explain better. b.s.171

[kluth]

Thanks, Bill. I appreciate the info. Once I get started, I may have to take you up on that phone call.

Kirk

[kluth]

Bill, when you say "blow dry, seal, and paint", what do you mean by seal?

Kirk

[racingelvis]

blow dry is a term we use in the body shop after wet sanding. just blowing the water of the part until dry.
seal meaning, use a automotive paint sealer. comes in various colors. i use grey or white before spraying the rupp red color (paint code wa8774). you put this sealer on before you paint. the sealer does a # of good things, it makes the part you are painting one uniform color for easy painting, it will help fill sanding marks or scratches and helps paint hold its gloss. hope this helps. any more questions dont be affraid to ask!! thanks,.....b.s.171

[pathfinder]

Bill
This information is invaluable to me and a lot of others! I think we have all worked very hard doing over an older hood with stress cracks in it, sanded the hell out of it, primed it, painted it, and were disappointed when those cracks showed back up after all the work. This should give us rookies a shot at a decent finish with your tips. Someday when you have some time ( yea right! LOL!) you should consider doing a post with some "tips for dummies" with some pics at stages. I'm sure that would be very helpful to a lot of people.

path 8-)finder#6

[racingelvis]

lol, none of you guys are dummies, however that is a very good idea pathfinder and i wouild be glad to do this. the very next rupp hood i do that needs a repair like this i will do. great idea!!!! b.s.171

[badmoto]

Ive done alot of glass work , basically i do the same as bill with a few different things, first of get a sharpie marker and trace all of the spider cracks, (once you start sanding or grinding the dust hides the cracks so you cant see them thats why you mark them) then grind all of them out just through the gel coat with a round or tapered bit and ether fill them with catalyzed fiber glass resin or duraglass, then sand with 150 grit and do some light filler (glazing putty) work over the top ( I hate seeing spider cracks after you just put a hole bunch of time into making it look nice) then start priming and working your way up to 400-500 grit like bill said, seal , base coat , and clear it,

I have a post in the photo gallery on page 2 titled 76-77 nitro that shows pics in various stages through the paint
hope this helps

[pathfinder]

The magic marker tip is a good one, as you pointed out, once you start sanding a crack out, it disappears in the dust and makes you think your deep enough. This should help! Thanks for the info! It's all making a lot more sense!

path 8-)finder#6

[racingelvis]

thanks for adding to the post badmoto. we also do exactly what you said about grinding cracks and filling them. in my orginal post thats why i stated if there just normal spider cracks you can do what i had stated, but if there bad , ware you can see what i call a air gap crack, them yes they need to be ground and filled before any type of a primer can be applied.
i know every body does things there own way but one thing i highly disagree with you is the marker. there is absolutley no markers that touch the surface we are working on in my shop ever. if you do not get all of that marker off the ink from the marker will bleed throught bondo, primer, and paint and will come through to the top and you will see it so we dont even take a chance. not saying that you can mark something and get it off and never have a problem but it happned here once and never again is what i am saying. its just my rule in my shop, lol. again thanks for adding to the post though!! b.s.171

[badmoto]

YES VERY IMPORTANT YOU MUST GET ALL OF THE MARKER OFF OR IT WILL BLEED THROUGH!
I use a marker on every car that comes in , but I am the only body man here so I make sure it all gets sanded off, plus the painter here has a fairly good eye also , when you have a few guys doing various work through the job sometimes things get overlooked or forgot, I am a control freak with my work so i make sure its right before i send it to the painter, (on the cars, sleds I do both body and paint just to make sure its up to specs)

thanks for bringing that up Bill
Chaz

[pathfinder]

Bill
Can you elaborate on the difference between "spider cracks" and "air gap cracks"! As always, thanks for your input!

path 8-)finder#6

[racingelvis]

all good chaz, were on the same page!!!! you know i wasnt nocken your precedure it's just very important all the marker comes off completley like you said, or there will be a surpirse on your fineshed project,!!!

pathfinder, what i mean by a spider crack or a air gap crack is that on a normal fiber glass spider crack, those cracks are very minor cracks, you can see them, sometimes cant even feel them. they can be either long or short cracks through out the gel coat. its just that they are very minor cracks. these kind of cracks can usally be filled with a polyester filler or a primer filler. a "air gap" crack is a severe crack. the gel coat might have seperated leaving a air space between the cracks or the glass is just cracked that bad that there is a gap in the gel coat. those kind of cracks need to be ground and filled with resin or a body filler such as duraglass like badmoto had stated. if the hood is cracked-broken then you need to use fiber glass matting and resin to strengthen the hood back up before you do any body work. hope this helps!!! b.s.171

[sledaholic]

What are the 1974 Nitro hoods made of? I have one with a crack all the way through from the vent opening to the windshield area. I would like to use this hood as it is clean other than that. I am also looking for panels for my 1972 440 Nitro. Thanks

[racingelvis]

the 74/75 hoods are made of smc. (sheet molded compound) you can fiber glass to it, but it needs to be ground very good. where it is not ground, nothing will stick to it. we have glassed them up with resin and matting and have had great luck. the smc is a good material but more brittle than fiber glass, thats why you see those hoods cracked or broken in half the way they are.

i have panels in stock for your 72 nitro. let me know if interested!!, thanks bill

[ruppluver]

This is a VERY good thread!!! I use a Canadian product called"PolyAll 2000". It's a 2 part product,hardner & resin? You mix up 1 ounce of each,BUT you have less than 3 minutes to get it"painted" on. It took me 2 ozs of each to do one hood. It's thin like water,it gets into the cracks,when it dries it expands,filling the crack! All you do is sand your hood or whatever you want to fix,mix up PolyAll 2000 & brush it on. When it cures,you sand it ALL off. Prime/seal it,sand & paint. Here's a website to read more about it: www.polyall.com Ooops,sorry if I high jacked the thread.

[rupprat]

Looks like good stuff, and the distributor is just 6 miles up the road from me !

[magnesium]

Get enuff 4 all of us,then.Yer the best,Al!

[sledaholic]

Thanks Bill. They were perfect until one cold day when a friend leaned on the side cover. Sucks, but I never liked the plastic panels.Mine is pretty good, but have been looking for a replacement. Thanks Jeff

[sledaholic]

Just ordered the Poly-All 2000 you sugested. It had been ground out and filled with Bondo, but cracked. I like to fix things one time only and with the vent right there it is a stressed area. Thanks