Adding some weight and thickness to reproduced fg part

[tinhorn]

Some dude is selling CoreMat on eBay. Less than twenty bucks if you avoid the word-spamming clown from Wisconsin. ( http://cgi.ebay.com/ebaymotors/Core-...ssoriesQ5fGear )

I'd go with Herman's Option 1, in which case you can just use Bondo instead of all that fancy overpriced stuff your marine guy wants to sell you. In fact, you could use Bondo even if you decide to finish with gelcoat for some unfathomable masochistic reason. (Bondo is a polyester putty, and I've seen it used with polyester resin and/or gelcoat on many nonstructural parts.)

[swade]

Thanks for all of the advice, I've been tied up on the engine side of things and haven't added any additional layers on the back yet, I'll call around a bit tomorrow and check on some coremat before i go the just add more glass route.

I put my 1st layer of resin/qcell on the outside, i noticed checking the fitting of my piece, on one edge i need a little more build up...just 1 or 2 small strips of glass on the edge should do it, then faired into the rest. I contemplated building it up with more fairing material but that seems to thick and it's a hinge side as well.

Do I need to grind that fairing resin/qcell off there to bare glass to add the bit of glass? Or will it bond ok as is? The fairing is pretty light there just filling in the initial glass dips,etc since it's not from a mold.

Yes I'm surprised the fiberglass supply didn't mention qcell and recommended resin+cabosil, I've been testing everything first and glad i did!! That would have been a bear to smooth.

Small initial fiberglass project but i've learned alot for the next time.

[swade]

Yeah i read so many mixed things about bondo on various boards i just wasn't sure never having done this before. Seemed to me on this part it would be fine for light fairing as long as you don't have to put inch layers of it.

I knew the resin/qcell would be ok though and had gotten extra resin for my 1st run screwup and subsequent project if this came out. The fiberglass place isn't too bad, qcell was something like $7 for a quart, cabosil the same, resin was lots cheaper from the supply house than any marine, home store,etc. FG mat was insanely cheaper than those other places. Though a quart of bondo is what $9 bucks would have saved about $20 for sure.

Thanks for the ebay coremat link I was going to look there too.

[Submarine Tom]

"Do I need to grind that fairing resin/qcell off there to bare glass to add the bit of glass? Or will it bond ok as is? The fairing is pretty light there just filling in the initial glass dips,etc since it's not from a mold."

I would say it depends how structural that area is, that is to say, how much load it will have to bear. You lose a lot of strength when the fibers are missing in the matrix.

-Tom

[Herman]

I second to Tom. As fibers are already protruding, I guess it is OK for a lid.

About Aerosil / Cabosil: I recommend that in highly loaded fillet joints, but I also recommend cleaning up the place before the resin sets... Now you know why.

[swade]

Thanks all for the advice! I added 3 more 1.5 oz layers to the back (6 total now) it seems plenty thick and weighty with no flex now, added a layer or 2 additional to the fitting issue side (i went ahead and ground the fairing mix back in that area). Cut my edges with diamond blade on an angle grinder. sanded, Faired it all out with a diy sanding board and block. I'm pretty dang happy with the result so far never having done this.

I'll say one thing the resins setup up fast in florida in the summer with 95+ temps and 90% humidity, i cut the recommended mek proportions in 1/2 after seeing how fast my 1st batch went off initially.

I think it's ready to paint or gelcoat now after one more finish sanding.

Not sure what i'll do on that route, i'm leading towards spraying the gelcoat (or rolling if i can get it pretty smooth wet sanding, then using my random orbital polisher). Kinda leaning towards that as I have some hull areas that will need some touch ups and small repairs here and there so figured might as well try that.

Some of the videos i've seen on the web for spraying gelcoat they thinned with syrene or durtec, then compounded later, doesn't look all that hard but then again i said that about building a form, then glassing it initially too.

[swade]

What should I use for a final glazing putty to cover pinholes,etc? Bondo glazing putty? or something else? Or just a final resin coat?
From googling I see there's a product called evercoat glazing putty too..bit expensive that stuff

Thanks,
shannon

Filler paint,

and most probably several coats of it, before you get a smooth finish.

Cheap, durable and easy to work with.

Leave the gelcoat nonsense.

Regards
Richard

[Landlubber]

Filler paint,

what we would call two pack hi build......good stuff

[Herman]

Gelcoat is nice too. If you are masochistic...

Filler paint: whatever they call it, filler paint, hi build primer, sprayable putty, it does your job.

[waikikin]

[quote=Herman;380911]Gelcoat is nice too. If you are masochistic...
Hi Swade,
Gelcoat is nice & if your skilled in flowcoating quite quick to bring to a finish, if you've got a surfboard shaper/glasser nearby ask for a look at how filler & glosscoat is applied - it could be quite enlightening to many here & some board building forums might be helpfull too. All the best from Jeff.

[swade]

Hi All!

it's been awhile but I finally completed this part with the help from the forum

http://www.flickr.com/photos/32698314@N05/5167873453/
http://www.flickr.com/photos/32698314@N05/5167873629/

It's not perfect as I was running out of time to get it finished but I'm 95% happy with it...nothing major that drives me nuts I couldn't clean up later if I wanted to. Being my first time doing this the part was a bit of a challenge with all the curves and recess for the windscreen. I still have to hinge it and put a latch.

I ended up spraying it with gelcoat (for learning experience) which to me turned out to be the easiest part, I thinned it with styrene, sprayed with a cheap harbor freight gun, then simply wet sanded 250-1000 then compounded and polished (boy did that make a difference!...wouldn't want to do a whole boat that way though!).

Anyways thanks for all the help! ready to tackle a few smaller projects now.

Biggest problem was fairing everything out, some kind of high build primer under gelcoat would have made that easier but I wasn't quite sure what I could use with the gelcoat. I did use 2k high build to paint the motor and that worked out quite well.

In the 2nd picture the typical vinyled panel that the control/throttle is on, I want to make that a fiberglass piece (will probably put a recessed cup holder in it). I'm not sure if I should do like i did with the hatch and fiberglass over a foam or mdf male plug, or I *thought* it may be easier and I'd avoid a lot of fairing if I routed a cut out in the shape into MDF for a female mold, routed the edges, then waxed and layed the glass in that....any ideas on which would be better? It would seem I'd get a flatter surface that way with less fairing than laying glass over a piece I make and fair it all out afterwards but I'm not quite sure.

Thanks! shannon