1989 Chaparral Transom Repair

[rad1026]

Thanks WOG, I will use that chart. The one US Distributors sent with my order says 1/8 oz per 16oz at 80 degrees for a 15-20 minute set.

 

[Woodonglass]

When temps are in the 80's I usually use a 1.5% ratio. Closer to 1/4 oz. That's why I suggest using CC's. Much easier to calculate the % ratio.

 

[rad1026]

oops, I meant US Composites. Thanks WOG. Is there a chart for the CC or is it just a ratio?

 

[alldodge]

I use the little medicine cups, they have CC, ML, OZ, and TBS

 

[rad1026]

oh, ha, yeah I get it 1.5% ratio. I'm a little slow.

 

[Woodonglass]

The chart I sent you has the CC ratio listed too!!!

 

[rad1026]

Not like I will get this far over the weekend but I have seen two different methods of tabbing in the transom. One where he took 8" strips of 1708 and worked in the edges of the transom with two layers, the second one going wider then the first. Then two layers of 1708 over the surface of the transom. The other way was to cut 1708 larger then the transom and just work it all in at one time and then a second layer to overlap the first. Is one way better, more recommended then the other? What things do you need to watch out for if you are using the first method? Are there concerns with overlapping the fiberglass on the transom surface?

 

[Woodonglass]

Either way will work. Main thing to look for is air pockets in the glass layups. If you get any just grind them out and lay patches over those spots.

 

[rad1026]

kinda what I thought but wanted to ask. Thanks WOG. Hope I get a lot done this weekend, but having a graduation party Saturday for my son. College graduate and walks right in to a nice job. I'm pretty proud of him.

 

[rad1026]

ya know I've been around this I-boats since 2006. I'm only a Petty Officer 1st class, E-6. Guess I need to spend some more time in here. Who can survive on an E-6 salary??

 

[alldodge]

ya know I've been around this I-boats since 2006. I'm only a Petty Officer 1st class, E-6. Guess I need to spend some more time in here. Who can survive on an E-6 salary??

Just repeat what others say and before you know it, you'll be in the officers mess

 

[rad1026]

I guess that's one way. I really only chime in when I have something constructive to offer. I have had this boat since 2005 and the only time any one has done work on it but me was for my second bellows job that I just didn't want to do. I guess after this repair I hope I will earn a certain amount of experience. Here's to the smell of resin and the itching of fiberglass! Cheers!

 

[alldodge]

Right there with ya :thumb:

Glad to see your son make it good, shows he had grate roll models

 

[52FordF2]

I have been using a chart like this for Resin and PB

Resin Catalyst Percent Resin Catalyst Percent
500 ml ~ 5 ml ~ 1% 1000 ml ~ 10 ml ~ 1%
500 ml ~ 7.5 ml ~ 1.5% 1000 ml ~ 15 ml ~ 1.5%
500 ml ~ 10 ml ~ 2% 1000 ml ~ 20 ml ~ 2%

Peanut Butter Recipe
Resin Catalyst Percent Cabosil 1/4 Fibers Resin Catalyst Percent Cabosil 1/4 Fibers
500 ml ~ 5 ml ~ 1% 750 ml 37.5 ml 1000 ml ~ 10 ml ~ 1% 1500 ml 75 ml
500 ml ~ 7.5 ml ~ 1.5% 750 ml 37.5 ml 1000 ml ~ 15 ml ~ 1.5% 1500 ml 75 ml
500 ml ~ 10 ml~ 2% 750 ml 37.5 ml 1000 ml ~ 20 ml ~ 2% 1500 ml 75 ml

250ml ~ 2.5ml ~ 1% 350 ml 18.75 ml

8 oz = 236.588 ml 2.5 ml at 1%
16 oz = 473.176 ml 5.0 ml at 1%
32 oz = 946.353 ml 1000ml=33.814 oz 10 ml = 1% 15 ml= 1.5%

Temperature goes up, MEKP % goes down, Temperature goes down MEKP % goes up. Around 70 degree Fahrenheit

 

[52FordF2]

Also if you are in Thailand, do your Fiberglassing around 2:00 am in the morning at the smallest percent MEKp that you can. If you do it during the day, it goes off at the time you finish mixing :facepalm: in the MEKp.:joyous:

 

[rad1026]

I didn't get anything done this weekend. Oh well. This weekend for sure I'm going to get the transom in. Thanks for the chart Ford. Guess its a good thing I'm not in Thailand. Supposed to 80-82 degrees this weekend. Should be perfect.

 

[rad1026]

and 1ml=1cc

 

[52FordF2]

That correct. I normally use medicine cups that goes to 20 cc

 

[rad1026]

No Title

I finally got the transom glued up Sunday morning. I was so nervous. My son was supposed to come over and help but that just didn't work out. I got my wife to hand me the 2X4 clamps. I mixed up one container of 1.5l with a 1% hardener about 250ml of 1/4 chop strand and maybe 750ml of cabisol. That seemed to produce a pretty good mixture. I poured another 1.5l and added the chop strand. I got everything set up and spread the back of the transom piece then mixed hardener and cabisol in the next container and spread that on the transom. Got them put together and clamped. It gave me about 45 minutes which was plenty of time. I took the rest of the pb and started evening out the edges of the transom and the bottom. It set up like a rock. I was super happy with the outcome. I came back Monday morning and finished off with PB to even out the bottom of the transom and the top and side edges. While that was setting up I went across the street and got my in-laws evaporative cooler going. It was about 85? by then. I went back to the boat and sanded down any rough spots then cleaned with acetone then cut some 8" strips of 1708 and started tabbing the bottom. I mixed the resin too heavy and it set up too quick. I don't feel like I was able to wet those bottom tabs as well as I would like. I definitely got better at it once I reduced the hardener to give me some working time. It was harder then I thought. It takes a lot of working to get it all wet in. I used a roller, a brush with the bristles cut short and a metal bubble roller. I'm going to do one more layer of 1708 and then move on to the stingers and the engine mounts. It is like a tank. I am really not even sure I need to do another layer, but that was my plan and I'm sticking to it. So that will be one layer of CSM on front and back of transom wood, then 2 layers of 1708 to tab it all in.

 

[alldodge]

Nice looking job. Did you have much squeeze out from behind?