fiberglass keel, and chip repair?

[ziggy]

i'm askin this to soon, as i dought i will get to it till spring, but i'm just dyin to find out what kinda trouble i got. will i be fixin this from the outside or inside then outside. what products will i need to be researching. marine tex? or perhaps a little more effort is gonna be involved in this. what should be my method of attact be to repair this?
the damage is to the gel coat i assume, maybe into the fiberglass but don't know. the main damage is to the keel at the bow. it's been scraped down the trailer. got a few minor scraches down the side too. also showing the red fiberglass in a couple of spots. but very minor compared to this at the keel. it don't leak that i'm aware of, but i am concerened. here's my pics.

this pic is looking fwd twards the bow. ya can see the outline of the bow, perspective

lookin bow to stern, top of pic is most fwd part of damage.

rigt side of pic is bow, left twards stern

these are the chips. previous owner is responsible for the caulkin, i don't think that's a repair. what is the proper repair tthough?

just another chip. i've got several. all on the starboard side......


this is on my 75 aristo craft...........

 

[andy6374]

Re: fiberglass keel, and chip repair?

Unless my eyes can't tell...

It seems as if it's only gelcoat damage. I cannot see, from the pictures at least, that there is any signs of cracking or delamination of the fiberglass.

What I'd do is:
1. Grind back all the gelcoat until you knock off all the loose stuff.
2. Let it dry for a little bit. Water may have gotten inbetween the gelcoat and fiberglass while it was in this condition
3. Apply some fairing compound and sand smooth.
4. Then apply some gelcoat over the repair. It won't match perfectly, but it will be hidden under water. You can get pigments to add to the gelcoat to try and match the color exactly if you want.

If the fiberglass is damaged the approach will be different, let us know?

Will you be adding bottom paint?

 

[ziggy]

Re: fiberglass keel, and chip repair?

thanks andy, i think it's really only gel coat damage. the flakes ya can see in the picture won't just flake off. they're still stuck to the fiberglass. i'm not real sure what to look for as for delamination, but the exposed fiberglass has no signs of a crack or cracking and is still hard. least i can't penetrate it with my finger nail, and sounds hard when tapping on it. also can't just pick at the fiberglass and have it come off. i think the fiberglass is intact engough. though i do think i've lost a bit of thickness. though that would be hard to tell i suppose from the outside. guess i'm judgeing it by the height of the getcoat.
so what is fairing compound? is there a perticular product that works well for building up a little thickness. i don't suppose to much is in order as i recokon ya want the gel coat to be the same height as the old gelcoat. perferably white i suppose..
one other thought i had was to put me one of themz keel protectors on. that might cover some sins i suppose. but i would think even if i do that it'd be better to fix the gel coat in that area first....
this is a trailer boat so will not be gettin any bottom paint....

i guess i need to be researching a gel coat to buy and the proper filler. the surface of the fiberglass is rough. i suppose the filler will even that out though. sure appriceate yer comments. thankyou.....

 

[Bondo]

Re: fiberglass keel, and chip repair?

so what is fairing compound?

It's Putty,.......Like Bondo.....Not Me, but the Autobody Filler.......

In Your case, I'd be mixing my own, with Epoxy as the base Resin, rather than Polyester like Bondo.....
For Fillers,... There's quite a few, Cab-o-Sil comes to mind....
If you use an Epoxy based fairing mix, you could forget about the Gelcoat,+ just put your Keelshield right over the Repair.....
Or,..... Forget about the Gelcoat Anyways,+ Paint It,.... Much Simpler,+ Easier........

For Prep,...... I'd just Pick the Gelcoat back that's Loose, with a putty knife or something similar,....And, Dig out what looks like 5200 that was Gobbed into the 1 hole....
Then Sculpture,+ Smooge it back into shape with your Fairing mix......
Sand it out,+ Paint it,....
You're Done.......

 

[andy6374]

Re: fiberglass keel, and chip repair?

Like Bondo said, unless you use vinylester or polyester resins you can't use gelcoat. But I really don't think it is necessary to use epoxy.

For the fairing compound:
-Get some vinylester or polyester resin and make sure you get a good top quality "marine grade" resin suitable for marine construction and repair. Not Bondo resin
-Mixing in just cabosil will make for a putty that is a beast to sand, but can be done. Instead I'd mix in some microballons until you have a mixture that has a thick gravy consistency. Then add cabosil until it becomes a peanut butter consistency (ie, thick enough so it won't sag on the vertical surface.).
-Spread it on and feather the edges then sand with a hand block or DA until fair.
- Then gelcoat the area.

You could also get a quality polyester glazing putty at the autobody shop and this will work fine too.

If you need to build up more than 1/8" then you can't just use the filler. You'll have to build it up with some glass first, grind it it ~ fair, then apply the fairing compound.

 

[ziggy]

Re: fiberglass keel, and chip repair?

it sounds like perhaps i'm makeing this out to be harder than it is. would this be a good filler. 3m marine high strength filler. it's "A unique vinyl ester formulation designed with short strand fiberglass for semi-structural repairs, above and below the waterline."
then, if it ain't thick enough for a vertical surface, put in some cab-o-sil or micro ballons to thicken it up a bit? then some gel coat over it. like the gel coat that iboats sells?
i'm i gettin the right idea?
haveing never done any repairs like this, i'm haveing a hard time decideing the exact product to use as there is so darn many products out there. i'm overwelmed in looking for the right one. and i'd prefer to try and use the right product for my application the first time i try, if possible.........thanks for the help folks, i sure do appriciate it...........

 

[Bondo]

Re: fiberglass keel, and chip repair?

I think you need aFiller Without the Fiberglass Strands in it,.....

You need something with a Smooth Consistency,......

You're not filling a Big Hole,..... Just alittle Scuff Damage......

Personnally,..... I'd Skip the Gelcoat,+ go with Paint,....
It'll save you Tons of Sanding......

 

[andy6374]

Re: fiberglass keel, and chip repair?

That 3m filler is the only product sold by 3m that I would never recommend.

That being said it sounds as if you don't want to make your own putty and that is fine! I hardly do myself unless I am making structrual putties for fillets or bonding.

if you are going to paint, get some system 3 quik fair (epoxy based).

or if you are going to gelcoat get some Evercoat polyester glazing putty.

 

[ziggy]

Re: fiberglass keel, and chip repair?

so of 'all' the 3m products ( & they sure do have a gob of different products too) i picked the wrong one. amazing.... glad i'm asking the question now. thanks for saving me a headache.
i looked at the 3 quik fair and that looks like it might work good. if i use that will i be able to paint it, or gel coat it. i guess from reading it seems that gelcoat don't stick to epoxy real good. does paint stick? or perhaps i could use some color additive? i like bondos idea of less sanding. i may or may not put on a keel protecter so guess i'd at least like white in case i don't. looks like the 3 quik fair drys tan. but i've seen some pigments for mixin with epoxy. is that what i'd be useing to get white?
the evercoat looks like it'd be ok too, but i don't see anything that says it's ok to use below the waterline. this is certainly below.
i haven't cleaned out the caulk yet (refering to the holes now, not the scrape accross the keel), but expect to find a pretty deep gouge. sure hope it aint thru the fiberglass. i'm gonna have to wait to find that out till i'm ready to do that. i suppose that if it is a hole i will be repairin differently than if it don't go thru. assumin it aint thru. would i be able to use the 3 quik fair there also?
i spoke of the marine tex. which is epoxy based from what i read too. is there some benifit of 3 quik fair over the marine tex? niether of you have suggested i use marine tex. why is that? i guess i'd have to assume that these products have different uses.
andy, i'm not opposed to mixin my own. but once again, i don't know what products to mix. i suppose kiss would apply for me. keep it simple stupid, as i am not educated in this repair. the simpler the better for me i reckon. i just want a good repair that will protect the boat. water intrusion into my stringerless foam only filled boat worrys me.
thanks for the comments guys. yer sure helpin me decide which product to use.

 

[andy6374]

Re: fiberglass keel, and chip repair?

The evercoat is fine below the waterline. You can use paint or gelcoat over evercoat.

If you use the system 3 quik fair you can only paint...no gelcoat.

Happy Sanding 8)

Just in case you wanted some pics...
I replaced the transom in my Mako. The outside transom skin was stress cracks everywhere, including plenty of low spots. I filled the low areas with 1.5 oz mat, then grinded fair. Then I applyed the polyester glazing putty (Evercoat) to the low spots, then sanded fair. Then I applied a thin skimcoat over the entire outside skin and sanded it smooth. Then I rolled on the gelcoat.

Before:

After transom replacement and first pass at leveling the transom skin

Final product:

You WILL get orange peel if you roll it and even if you thin it will something like duratec high gloss and spray you'll still get some peel.

Surface before wet sanding:

After:

 

[ziggy]

Re: fiberglass keel, and chip repair?

thanks for the pics andy. yer project looks like it came out real good. nice job. thanks for lettin me know that the evercoat is ok underwater. now i have food for thought. do what you did with the evercoat and gelcoat. or some hard sanding 3 quik fair and paint.....guess i have a little time prior to doing anything cause of the fine cold weather which is why i ask now. i appricate all the comments.....i'm gettin my plan together................