Shaft Log Upgrades

[conchy joe]

Hello faithful, I am in the process of following Capt Pat's building tips to do my fiberglass shaft logs on my 28 Bertram FBC. I have sawed out the factory fiberglass dimples which make a bigger hole than the 31's bronze logs. Anyhow I about to glass in a layer of fiberglass to fill in the hole before cutting a properly sized hole for the fiberglass tubes as detailed in the building tip.



I have been using a decent grade of polyester resin from http://www.FGCI.com for all my engine room repairs and still have five gallons left. I know that its not an adhesive, where epoxy is and I would prefer to use epoxy on this project, however I'd rather not spend the additional money if the polyester resin will work. Additionally I have been using a product called ATPRIME between the old lamination and the new.

Here's how the manufacturer describes the product:
ATPRIME® 2 is a two-component urethane-based primer system developed to enhance adhesion to FRP in secondary laminating operations, including bonding to non-air- inhibited surfaces. The material is applied with a brush or roller to prepared surfaces. Bonding is formed chemically.
ATPRIME® 2 significantly improves interlaminar bond strength when used with Atlac® and Dion® resins. It will also enhance bonding of FRP to concrete, bright carbon steel, and thermoplastics such as PVC.

My question is, although the polyester resin is not the best product for the job but will polyester resin make an acceptable repair?

[RussP]

I'm sure polyester resin would work but it would be a rather large hole if it fails. Spend the money on epoxy resin
and sleep well at night.

RussP

[CaptPatrick]

Troy,

Yes you can use polyester, BUT ya' gotta' cross all your T s and dot all your I s...

Definitely use the ATPRIME® 2 as a tie coating. I'm not familiar with the product, but am with the concept. Do a minimum of 12:1 scarfing and grind those surfaces with nothing finer than 60 grit. 36 grit would be my choice. Use the same technique as outlined at http://bertram31.com/proj/tips/hole_patch.htm

After the holes have been configured, scrub them down well with acetone and apply your tie coating. Make sure that every sq mm is wetted out well and wipe away any excess resin. Surface needs to be wet out, but not dripping wet. Allow it to tack up and while tacky, apply your first layer of glass. From there on stay within a 24 hr schedule to finish glassing between each layer. Repeat the process when glassing in the tubes...

Br,

Patrick

[CaptPatrick]

And yes, Russ is very correct!

[conchy joe]

Thanks Capt Pat, I feel more comfortable in doing the job now. Will keep you posted.

[conchy joe]

I was hoping to get at least one side done over the weekend, but Isaac had other plans, so today I started grinding and ran into an obstacle. My rudder supports come all the way forward and butt up again the shaft log hole.

Should I cut the support back about 5-6" and then continue the scarf or what?


Untitled by nitroxgod, on Flickr

Also when I post photos they are not displaying I only get the box above. I'm using the IMG button above to post the code and am inserting the following link.

http://www.flickr.com/photos/79792193@N02/7873654266/

Any ideas what I'm doing wrong? The img /img code line is the code being generated by the buttons above. Its enclosed by the [] []

[CaptPatrick]

Posting images from Flikr first...


In your Flickr album, click "Share", click "Grab the HTML/BBCode", click the radio button that says "BBCode", copy the code and paste it in the body of the message you're composing. Add no others tags and skip a space between images if posting several. Notice that for an image to be readable, it must end in .jpg, .gif, .tif, or other type of single image file extension.

Code: Select all

[url=http://www.flickr.com/photos/79792193@N02/7873654266/][img]http://farm9.staticflickr.com/8432/7873654266_3cb609b838.jpg[/img][/url]
[url=http://www.flickr.com/photos/79792193@N02/7873654266/]Untitled[/url] by [url=http://www.flickr.com/people/79792193@N02/]nitroxgod[/url], on Flickr

Untitled by nitroxgod, on Flickr

Notice that Flikr has 2 parts to the code:

Part A: Which is all you really need

Code: Select all

[url=http://www.flickr.com/photos/79792193@N02/7873654266/][img]http://farm9.staticflickr.com/8432/7873654266_3cb609b838.jpg[/img][/url]

Part B: Realitively meaningless since the image is already linked to your album.

Code: Select all

[url=http://www.flickr.com/photos/79792193@N02/7873654266/]Untitled[/url] by [url=http://www.flickr.com/people/79792193@N02/]nitroxgod[/url], on Flickr

And only adds the redundant snippet below:
Untitled by nitroxgod, on Flickr

I'll deal with your actual project in the next reply...

[CaptPatrick]

Should I cut the support back about 5-6" and then continue the scarf or what?

Short answer here: Yup...

Br,

Patrick

I may not be smart enough to do everything, but I'm dumb enough to try anything...

[Harry Babb]

I may not be smart enough to do everything, but I'm dumb enough to try anything...

Like Robert says on Everybody loves Raymond....."Is this about me"?

Pat....that's a good one.....I love it!!

hb

[CaptPatrick]

Don't remember where I found that byline, but I stole it anyway... Hey, I resemble that remark!

[Bob H.]

That line sure sums up my whole project....had a good laugh...BH

[CaptPatrick]

Goes along with a stolen song line, "I ain't as good as I once was, but I'm as good once as I ever was..." ( Toby Keith )

[Marlin]

Troy, I would not consider anything but epoxy,chemical bond,glue, polyester requires a lot of mechanical interaction to maybe work, big hole, follow capt Pats suggestion on the amount of grinding per thickness, do this on inside and outside, cut out the patches in increased graduations and lay up a saturated sandwich on the inside, may need some external supported backup to keep the sandwich from falling thru, the backup piece should be insulated with a piece of visqueen so u can separate the backup , apply the same sandwich from the outside and reapply the insulated support pad, propped up to hold tight to the bottom of the hull, go back inside and roll out the inner patch with a bubble breaker to get rid of the air bubbles and get a consistent ,rich layup, epoxy gives u the time to do this, polyester in our climate will kick off to fast,then u have regrong this area to create to create the mechanicanical bond, the capt refers to this as a tooth to lock in the polyester, I would use a biax cloth as well, my go to guy was Pedro and I know Spencer used him as well for glass repairs, he is currently helping me on another project but I can loan him out, talented guy, went thru 30 gallon of epoxy on my project,let me know, just across the intracoastal

[mike ohlstein]

Don't use the fast hardener. If you need more time, set your pot on top of an ice pack while doing the layup.

[Rawleigh]

Also, my vote would be cut out the old rudder supports and let the new support come forward and cover your patch and the shaft logs stinger to stringer. One large plywood support. Scarf the edges and bed it in Capt Pats blend of epoxy and vermiculite. Glass over the whole thing. It will give you a whole lot more support if you ever have a shaft or rudder strike.