olysan

I'm in the demo phase of a transom repair/replacement project on my boat. It is an 89 Mach 1 ~24' with a 406 SBC. Nothing exotic. I'm looking for some advice on glassing in the new wood. Questions:

1. I will be using an epoxy resin, but Id like to hear what is the recommended brand and where to get it. I plan to do this in the next few weeks so I'll probably need a warm weather formula if available.

2. Is there an advantage/disadvantage to using either "E" glass or "S" glass cloth?

3. What weight cloth should I use and how many layers (Inner transom)?

Thanks in advance for the information.

Regards
Mike O.

olysan

I don't think I have PM privleges, but to answer your question I'm in the St. Louis area. You could email your number to [email protected], or you can call me on my cell @314.852.3579. Thanks.

excalibur32

West system for sure, S glass is much stonger than e glass kevlar and carbon forget them, not really much of a weight savings and the cost is horrible. Roving is strong but is used to add thickness faster.

olysan

I read through some of the threads regarding transom replacement last night. Very informative and also inspiring. You guys have done some great projects. I'm now thinking that I need to use biaxial 1808 which I saw referred to numerous times, I think originally recommended by glassdave. I'm also leaning towards the 635 epoxy that he recommended.

I've noticed alot of references to grinding in these threads and I'm wondering about the intent and tools used for this.

I'm assuming that grinding is done as a final prep before glassing to clean everyting up remove any lips etc, and also remove any old paint so that the existing glass will accept the new stuff. I guess for exterior work it's also important for blending the new with the old. Does that sound right?

What is the tool of choice for this? Will a 7" rotary sander/polisher with heavy grit paper get the job done?

Regards
Mike

Audiofn

The grinding is the part that SUCKS. My suggestion is first dump baby powder ALL over your body and rub it in. Then get a tyvek suit and tape the ankles and wrists. Then get one of those Sock hats and put that on your head and a GOOD mask (not those paper pieces o chit) and glasses. When you are done grinding for the day then take a shower and try and get the soap on ya as quickly as possible it helps float out the glass from your skin.

I use a 5" high speed grinder to grind. It is an air tool. You could use a buffer style grinder but they can be a pain because they are so large.

Most people cut out all the wood then just take off any sharp edges on the tabbing and then rough up the rest of the stuff. On my boat I actually removed ALL the old tabing. It takes a LOT more time to do this and I am not sure that there is any real world benifiet to it but that is what you get when you are OCD.

jackhammer

I converted a normal 4 1/2" grinder into a 7 inch by taking off the guard and putting on the plastic adapter to use 7" sanding discs. 26 grit discs cut it down fast. I burned up a couple Home Depot $39 disposable ryobe grinders. They get full of dust pretty fast.

The slow non-blushing 635 from us composites is VERY user friendly! http://www.uscomposites.com/epoxy.html Even with shipping it was only about $35/gal. I used it in the Texas heat without too much trouble... but below 70 it's take a couple days to dry.

Hang out here for a while and you'll be teaching the local glass guys a trick or two. Glassdave, Offshore Ginger, Audiofn, Zanie and that book I forwarded to you really helped me through it.

The biggest rookie mistake I made was not making it flat (or hull same thickness I should say) for the new wood. Whatever countours you grind on the inside will transfer to the outside when you bond the new wood in. I had the transom thickness at the drives ~1/4" and out by the sides ~3/8". had to fix that snafu by adding glass to the outside!

I didn't mind the grinding so much... I would get into a zone. I did make the mistake one time of not wearing my tyvek suit... only once did that happen!

Good luck and post pics!

olysan

Thanks for the info guys. G.G. I did not get your email.

Regards
Mike

olysan

Jackhammer,

How much of the 635 did you go through. I think I'll be doing a layer of 1.5 oz mat (epoxy compatible) between the old glass and the new wood, then a layer of the 1808 biax on the inside, and maybe some extra 1808 strips to reinforce around the edges. Does that sound right?

Where did you use the cabocil and chopped strand recipe?

Mike

jackhammer

The trick is to get your transom back to the correct thickness. Mine was 2-1/4" so I used two layers 3/4" plywood. My hull was about 1/4" thick or so. What I did was glass both sides of both pieces using 2 layers of the biax. For these I bought my glass off ebay. It came in big triangles and odd shapes, but for $20/50lbs I didn't mind the odd overlap and a little extra work. I used thickened epoxy (with cabosil) and made it as thick as peanut butter and I used one of those floor glue trowles to APPLY it to the hull.

EDIT: Removed all reference to the word "goop", which I incorrectly used as both an adjective and a verb (and it obviously offended excalibur32). In one case I meant to describe how the mixed resin/hardener/cabosil looked like "goop", and the other case I used the word to describe how I applied it "gooped". This would have meant I 'gooped' the 'goop' which I now understand could be easily misinterpreted.

jackhammer

In this pic I've circled some of the pieces that I put on after tabbing in the stringers. I just cut the wood on a 45. Here I used plenty more cabosil/strand recipe GENEROUSLY APPLIED to assist in the adhearance of the vertical pieces (Which by the way is how the factory did it before me). I then tabbed those pieces in too FOR STABILITY and to avoid killing myself and my family!!! Aaahhhhh!!! For the tabbing I used heavy stuff on the long straight stringers and the light stuff when I had lots of bends.