Geronimo - fiberglassing hull done

Designs for inboard or outboard power

Moderator: BruceDow

Post Reply
bobinpowayca
Posts: 430
Joined: Thu Jun 16, 2011 1:40 pm
Location: Poway, CA

Geronimo - fiberglassing hull done

Post by bobinpowayca »

Howdy, I just got the last coat of epoxy on my Geronimo's hull. I started with two encapsulating coats, then a coat on the 7 oz. cloth, then two more finish coats. I think it's pretty smooth now, I know I got the earlier coats on too thick because when it was sanded it looked like a big brown whale shark with hundreds of white spots! I did all the sanding with rubber sanding blocks and sanding boards, 80 grit. It doesn't show in the picture but I sanded a one inch wide flat area along the stem from the breasthook to where the skeg begins, and a 1 1/4 inch wide flat area the length of the stem - for attaching the stem cap and skeg which will be white oak. So here's what I'm wondering..
Should I go ahead and paint it - then install the stem cap, skeg and spray rails? This would work if I don't paint these members but just epoxy them. Or do they need to be covered with fiberglass cloth as well? Or should I attach them before painting the hull, and just mask them off?
Also, the instructions say to attach with "mastic" - as I remember from long ago mastic is a really sticky messy adhesive. Is this because you may want to remove them someday? Or should I just epoxy (as well as screws) them on? What is 5200 sealant? Any ideas on attaching skegs etc. is appreciated! Thanks, Bob
Attachments
IMG_0247.JPG
Bob
_______________
Built the Glen-L 17 (1988), Geronimo (2018)
PBR support (1968)

bobinpowayca
Posts: 430
Joined: Thu Jun 16, 2011 1:40 pm
Location: Poway, CA

Re: Geronimo - fiberglassing hull done

Post by bobinpowayca »

whoops, meant to say a 1 1/4 inch wide strip the length of the skeg on the keel.
Bob
_______________
Built the Glen-L 17 (1988), Geronimo (2018)
PBR support (1968)

kamisue
Posts: 32
Joined: Sun Apr 19, 2015 7:50 am

Re: Geronimo - fiberglassing hull done

Post by kamisue »

bobinpowayca wrote: What is 5200 sealant?

I can answer that :) 3M 5200 is a submersible sealant that comes in a tube and applied with a caulk gun. I found it at home depot and west marine. You can get various colors. It takes well over a day to firm up or at leat it did for me. It is pricey. I paid up to $14 a tube for it.

User avatar
Bill Edmundson
Posts: 11867
Joined: Wed Nov 23, 2005 6:45 am
Location: Birmingham, AL, USA
Contact:

Re: Geronimo - fiberglassing hull done

Post by Bill Edmundson »

Bob

I don't use 3M5200 very often. It's very messy. And, the stuff is so strong the that something is going to break if you do try to take it apart. It is permanent.

Bill
Mini -Tug, KH Tahoe 19 & Bartender 24 - There can be no miracle recoveries without first screwing up.
Tahoe 19 Build

User avatar
mrintense
Posts: 3617
Joined: Thu Jun 10, 2010 11:22 am
Location: Austin, Texas
Contact:

Re: Geronimo - fiberglassing hull done

Post by mrintense »

bobinpowayca wrote:Howdy, I just got the last coat of epoxy on my Geronimo's hull. I started with two encapsulating coats, then a coat on the 7 oz. cloth, then two more finish coats. I think it's pretty smooth now, I know I got the earlier coats on too thick because when it was sanded it looked like a big brown whale shark with hundreds of white spots! I did all the sanding with rubber sanding blocks and sanding boards, 80 grit. It doesn't show in the picture but I sanded a one inch wide flat area along the stem from the breasthook to where the skeg begins, and a 1 1/4 inch wide flat area the length of the stem - for attaching the stem cap and skeg which will be white oak. So here's what I'm wondering..
Should I go ahead and paint it - then install the stem cap, skeg and spray rails? This would work if I don't paint these members but just epoxy them. Or do they need to be covered with fiberglass cloth as well? Or should I attach them before painting the hull, and just mask them off?
Also, the instructions say to attach with "mastic" - as I remember from long ago mastic is a really sticky messy adhesive. Is this because you may want to remove them someday? Or should I just epoxy (as well as screws) them on? What is 5200 sealant? Any ideas on attaching skegs etc. is appreciated! Thanks, Bob
Bob,

I have not gotten to this point yet, but I am planning on the same three items. I am going to flatten the stem and keel seam for the skeg and stem cap, then fiberglass, then install the skeg and spray rails, then paint. The stem cap will be installed down the road (probably well after the flip).

I am NOT planning on fiberglassing over the skeg or the spray rails after installation. However, I might fiberglass the exterior surface of the skeg before I install it. The spray rails and skeg would be difficult to fiberglass over after installation with air gaps in the corners. I suppose you could fiberglass over the spray rails before installation as well, but I have a feeling these are going to be difficult to install even without the extra stiffness of the fiberglass.

One option you could consider on the spray rails is to apply fiberglass tape but avoid having it transition to the hull. In other words simply apply to the spray rail for abrasion protection. This could be done after installation. If you did want to transition the fiberglass to the hull, you would probably need fillets along the entire length of the spray rail.

Perhaps someone else will respond to this particular question.
Carl

Crafting a classically styled Vera Cruise

Clipper Boating

hoodman
Posts: 2379
Joined: Thu Nov 10, 2011 8:48 am
Location: Lafayette, IN

Re: Geronimo - fiberglassing hull done

Post by hoodman »

I can't speak from personal experience but of all the builds I've looked at on this forum I don't believe I have seen anyone mention fiberglassing the spray rails. It's probably not worth the effort. I think those extremities are considered sacrificial, although I think a lot of folks epoxy them on. I think if you exercise a normal amount of care while boating you wont ding them up too often. The white oak should be able to take a good amount of abuse, I've noticed my frames can take a pretty good bang from my No. 5 hand plane. :wink:
Matt

Building a Geronimo......!
viewtopic.php?f=2&t=25139

hoodman
Posts: 2379
Joined: Thu Nov 10, 2011 8:48 am
Location: Lafayette, IN

Re: Geronimo - fiberglassing hull done

Post by hoodman »

Your hull looks really nice by the way.
Matt

Building a Geronimo......!
viewtopic.php?f=2&t=25139

User avatar
Bill Edmundson
Posts: 11867
Joined: Wed Nov 23, 2005 6:45 am
Location: Birmingham, AL, USA
Contact:

Re: Geronimo - fiberglassing hull done

Post by Bill Edmundson »

Spray rails and rub rails are usually consider sacrificial. They are as much a bumper as anything. Spray rails are not optional in my opinion. That is unless you just like to get wet in cool weather.

Bill
Mini -Tug, KH Tahoe 19 & Bartender 24 - There can be no miracle recoveries without first screwing up.
Tahoe 19 Build

bobinpowayca
Posts: 430
Joined: Thu Jun 16, 2011 1:40 pm
Location: Poway, CA

Re: Geronimo - fiberglassing hull done

Post by bobinpowayca »

Thanks for the ideas. As for the skeg I don't really see me flipping the boat someday to replace it, so I think I'll go ahead and epoxy and screw it to the keel. I like your thought on glassing it first Carl; I wonder if the glass imparts any impact resistance. By the way what's the difference between a spray rail and a rub rail as far as their locations on the hull??
Bob
_______________
Built the Glen-L 17 (1988), Geronimo (2018)
PBR support (1968)

User avatar
chugalug
Posts: 1424
Joined: Sat Nov 29, 2014 5:01 pm
Location: top of mn.

Re: Geronimo - fiberglassing hull done

Post by chugalug »

Maybe you could use 4200 instead of 5200.Jamestown Distributers has some good deals sometimes.and I'm always offered free shipping on orders over 50 bucks.I laminated 1-1/2 inch strips and put fillet of epoxy in corners of my Bo-jest skeg then rounded over the bottom of skeg.each layer is epoxied together and first lam is epoxied to keel.Used a stiff sandpaper wheel from auto-body sander and curved that and hand-sanded fillets.then when I fibreglassed hull,I also put cloth on skeg.After waiting a week for fiberglass to cure,I washed hull, and lightly sanded and applied bottom paint to hull to estimated waterline. :D
Working on regular-sized Bo-Jest


"If it's not crooked,It's not mine

bobinpowayca
Posts: 430
Joined: Thu Jun 16, 2011 1:40 pm
Location: Poway, CA

Re: Geronimo - fiberglassing hull done

Post by bobinpowayca »

I think I will epoxy the spray rails and skeg to my boat before painting, without glassing. The spray rails will look nice unpainted. I may make the stem cap of the same 1" white oak, I know boiling water will bend it and that too will look nice unpainted. I was looking at the half-round solid back brass and stainless on Jamestown's site - I was thinking of SS for the stem cap but I'm wondering, has anyone bent this stuff - I'll be using one inch wide and wonder if you can bend this material the curvature of the stem?
Bob
_______________
Built the Glen-L 17 (1988), Geronimo (2018)
PBR support (1968)

User avatar
Locutus
Posts: 123
Joined: Thu Feb 26, 2015 9:23 am

Re: Geronimo - fiberglassing hull done

Post by Locutus »

Tip when using 5200:
After applying and inserting fasteners, tighten just snug. Wait at least a week for the 5200 to cure. Then tighten to correct torque. This will improve the seal.

Post Reply

Return to “Power Boats”