c_deezy

iTrader: (1)

I did my transom layup pretty much like the picture glassdave posted. Only exception was I mixed up some resin and cabosil and troweled it on the transom before putting my first layer of CSM/3/4" plywood on.

A few suggestions from another first-timer:
1) Dry fit your wood before you start doing any of the wet work and get your clamping system figured out. Once you start mixing up the gallons of resin you'll need things can get out of hand quick, so you don't want to be trying to figure out how to get it all clamped at the last minute.

2) Seal all of the plywood with unwaxed resin before the day before installation. This will keep the wood from pulling the resin out of the fabric when you do the layup.

3) On my initial install I just did the plywood first and clamped things all together, let that cure, then did the filling in around the edges and final two layers of 1708 and tabbing on the inside. Most people recommend laminating the two pieces of plywood together outside the boat, then installing them as one, I did not. I put them in individually. The thought being that they could move around and straighten out as things were clamped. I also put the CSM on the inner side of the plywood, on the work bench before installing in the boat.

The weather helped when I was doing mine, it was early spring and I kept the shop around 65 degrees to give a little longer working time. The 435 resin seems to have a pretty good working time anyhow so as long as you plan things before you should be ok. You also have a slightly smaller transom surface than I did with your notch so that will help too.
Looks like a good start. I used about 7 gallons of resin on my transom, but I did build up the original skin first. I went from about 1/8" thick to 3/8" on the skin, so that probably used a couple gallons.

Are you going with the 18oz cloth instead of biax to keep a consistent look with the rest of the boat?

38 X

iTrader: (1)

Yeah unfortunatily we will be doing this in 100 degree texas heat....think it's gonna kill my working time with the resin, but it will allow for a little fast cure time inbetween layers but and i was thinking of sticking with the plywood assembly with the matting and dropping it in whole with the measure twice cut once theory. Yeah i was gonna use the 18oz on my stringers before i realized the whole transom was coming out but yeah i was gonna use it to maintain the same thru out the hatch..... a bit overkill you think? yeah i'll definitly order mor resin...never want to run out in the middle of working it....Thank you again for the help anytime you want to visit houston let me know and i'll buy the tickets!!!

glassdave

iTrader: (1)

you have two other things going in you favor. Notch transom and exhaust above the rub rail. Much easier to do a short transom like that.

I prefer to pre laminate the two pieces together on the bench then test fit one more time and adjust before bonding in. My thoughts are it is more likely to help keep the transom true and flat while setting it in. Its important, as deezy said, to dry fit the wood but it goes for everything. I dry fit laminates as well, fit the first pattern then you have a perfect template for the second.


The heat is gonna be tough to deal with even with a standard mix it will go off fast. You wont need the benefit of a fast cure between laminates for any reason. It is going to be important to do this in specific stages to separate some of the processes from each other to allow resin working times to be independent. When i get home tonight is i am not to exhausted i will try and whip up a complete progression of the process that will help deal with fast curing in that kinda heat. Wish you were closer, i am considering looking for a good transom job to highlight and document.

38 X

iTrader: (1)

Thank you Dave..that will be the direction I take, for certain and all the help is greatly appreciated. And no rush on the process man get you some well needed rest, I have about another 7 days here before I make it home and start to tackle this! We have plenty of time to get it worked out, I just need to get what I'm lacking in materials ordered so it can be sitting awaiting my arrival! Anytime you want to jump down here you let me know...plane tickets are cheap!!

glassdave

iTrader: (1)

starting with a bare ground transom surface

1- cut your two pieces of transom wood and do a preliminary fit, adjust as nec. Dont forget to radius the top edge of the transom where the fiberglass will need to transition over it.
2- cut two pieces of ounce and a half CSM in the shape of the wood you just fit. Cut two pieces of 1708 using the wood as templates but leave yourself plus five or six inches around the perimeter
3- laminate the two pieces together using one of the CSM patterns. On a flat surface clamp,screw or weight them.
4- re fit the assembled piece and adjust as nec.
5- wax the outside surface of the transom with a good marine grade wax and drop a section of masking paper below each drive cut out. This step helps keep resin that oozes out the back in check. You can also tape over the small holes
6- wet out the mating side of the new transom and then wet out the inside fiberglass surface of the transom and apply the other piece of CSM wetting it out with the roller. Re wet the mating surface of the new transom as it will have soaked in some resin by now.
7- set transom in and use every screw and hole on the back to draw it in, generally you will have to slide the new transom up ever so slightly to get it to set perfect. I use two inch drywall screws and small fender washers with 3/16ths holes, try and start in the middle and work toward the sides and sneak up on it. I also have a half dozen or so of those cheapie adjustable screw jack cargo bars from harbor freight to apply pressure where there are no holes. You should get resin pooling at the base inside, if its clean take a brush and use it to start the hot coat on the inner surface but you probably wont get to awfully much out though.
8- Now that the new wood is set and screwed down it tile to work on the gap around the perimeter. A well fit transom will still have some inconsistencies and gaps around the edge. These will need to be filled with a paste of resin and cabosil mixed to the consistency of peanut butter. Using a yellow bondo spreader trowel in the filler taking care to leave a nice uniform flush even surface, kinda like icing a cake.
9- brush a hot coat of resin mixed at 2% over the entire inner surface of the transom

leave all this set up overnight . . . . go have a beer

9- using a DA or a small 3" angle grinder, both with 36 grit, clean up the edges and make sure the edge fill is flush with the surface of the new wood transom. De bur the whole thing even the hot coated wood, just drag the DA/36 over all of it and knock the tops off any runs or anything.
10- dry fit the two pieces of 1708 and adjust as nec, its ok to cut fit corners if need be.
11- downhill run from here. I use cheap general purpose paint rollers from home depot to liberally apply resin to the transom as evenly as possible. Once you have the whole thing coated set in one of the patterns of 1708 and continue to wet it out using the roller and a brush around the edges. Get it as balanced as you can but it is easier to to do the final balance with the second layer on. Once you have the first one in and wet out set in a layer of tabbing around the edge then put in the second layer. Wet out as you did the first. Once you have the entire lamination saturated its time to start the balancing process. Most first time do it yourselfers tend to whale on more resin and over saturate the stack of laminates. What you really want it a well balanced ratio of roughly half resin and half glass. One of the best ways to do this is to squeegee out excess resin using a new yellow bondo spreader. Work out the excess from top to bottom (or whatever works best for you) and pull out the resin with a paint brush. Works like a charm and your final surface should be matte or dull in appearance not shiny. I like to put in the final layer of tabbing after i have balanced it otherwise it can get in the way and become disturbed by that step.


This is just one way to do it as i am sure there are many variations but thought it could help give you some direction or a working knowledge of how itsdone. Kinda tired right now but i will have to proof read this later, may hafta make some adjustments lol.

38 X

iTrader: (1)

Dave I'm not sure if you have seen my supply list so far but do i need more resin for this? I was going to put in an order for 1708 and cabosil(could you please tell me what cabosil is ?and or what type of cabosil to get) but figured i would need more resin and also would us composites be a good place to pick up gel coat from if i need more of it? Ive seen you reccomend the PPG, but this is for the engine hatch or is the 2 gal plenty? While in this process i was also gonna try to get some paint layed on the top deck cockpit and sides just going back white for now, my gel coat is chalky do i need to sand it to the glass and re-gel before i repaint? If not what type of PPG paint to lay over it and how would i need to sand the gel coat with a 320-200 grit? Sorry, i know this is two totally different subjects...just trying to get preped for a solid week at home and get as much accomplished in that week as possible.

glassdave

iTrader: (1)

I couldnt remember are you doing the rest of the stringers to or just the center board? If you are doing just the center and the transom a five might just about do it but it will be close its really gonna depend on your ability to balance it. I would order the five and do the transom, at that point you'll know if you can squeeze the centerboard out of whats left although i think your gonna need another gallon or two for incidentals, if you are pinched for time on the project have seven gallons on hand and if need be you can get a decent 3M RESIN AT Home Depot or Lowes if you absolutely have to. Cabosil is a dry filler that is mixed into a catylized resin to make it a paste for filling gaps and voids, In your application you will need it to tighten up the gaps around the edge of the transom. I see you also have some mat tapes and a few other various fabrics in your order. The only thing you need glass wise is the 1708 bi-ax and the ounce and a half mat, no need for mat tape but you will need 1708 tape. I also see you ordered 38" width in the bi-ax, make sure this is wide enough to span the transom top to bottom, I usually use fifty inch and cut to fit but that is a pretty tall notch you have so ya might be ok there. Yes US comp also is a good place to get the white gel as well, you will either need a waxing agent or Duratech for a final cure though. If brushing the gel, the waxing additive will leave a satin finish but will cure to the surface, Duratech will leave a nicer harder gloss but does not cover as well.

Paint wise if you are going all white i use PPG's Concept single stage in fleet number 91050 white. DA the surface in 320 and go right to color, spot repair and prime any imperfections of course.

ridefast77

iTrader: (5)

For sure Dave is one of the most helpful and knowledgeable members on here, he has helped me a LOT on projects i have been working on. I don't think that we can thank him enuff thanks or credit for all the free guidance, knowledge and help he does for us OSO guys, i just want to say thanks Dave for all you do! And keep it up

glassdave

iTrader: (1)

lol


What a cool thing to say, thanks man. Ya know i have been asked many times why i dont advertise on here and actually its pretty simple, I'm here for social reasons i'm a boater and a do it yourselfer like pretty much everyone. I really get a kick out of seeing just how far ambition and talent (or the willingness to develop it) can take a person. Anyone that knows me also know how much i like to talk about boats (or any number of things really lol). Tell ya something else i have learned a thing 'er two just watching some of these projects and have had to say to my self more then once why the heck didnt I think of that lol.

38 X

iTrader: (1)

Well Dave is a greek god of boating in my book... Cannot thank ya'll enough for all the help....looks like we are gonna try to tackle this project this weekend and next week so i'll try to post up our progress as much as possible. Dave i must agree i haven't even been into the boating scene long and i already catch myself rambling on ... but i just like learning new stuff