1967 IMP Aztec -- Resto Underway again Suggestions please

oops!

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Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

bear with me here.....im trying to read up and see where you are....

as far as the problem described in post 56.. one csm....and three 1708 is great.

is the transom installed yet?.....if not...that needs to go in first.....so post back....and lets go from where you are.
 

rrumba

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Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

now...the stringers and bulkheads.
use pl if you want....all you are trying to do here is keep the stringer off the hull....place a thin wood (or even foam) shim on the hull under the stringer. then bed however you want.....for speed of the cure i like peanut butter.
tab the stringers with csm....after the tab cures...the stringer will stand by it self.....and you can glass it. i suggest one full layer of csm and one full layer of 1708 covering the whole thing. to wrap the stringer.....you can use csm or even cloth finishing veil...
the reason to glass before you add the bulkheads is to put a barrier between each stick of wood....kind of like a rot blocker.

This is kind of what i was getting at except i was going to tab both sides with 2 layers of 1708 then one wrap over the top to seal it. for the stringers as far as the width to use, i was going to use a 3/4" and 1/2" polyed together and for the engine compartment where i will be adding the new motor, i was going to add another 3/4" to each side of the stringer so it would end up around 2 3/4" thick then do like ROBJ did for his motor mounts and use a steel plated through bolted through the stringers.


as far as the transom knees...in an inboard situation.....the knees are not even neccasary...but if you want them (i did in my boat) just 6 or 8 ins is fine....then coat that with fiberglass for a water barrier.

Great...


oh...one thing.......whats up with that big round hole in the transom......shouldnt that look more like a key hole?

it's getting there, it will be that way shortly i promise. i just have to find the directions to find the X, and a template once i get the transom in so i can get it done as well.

Thanks for the info OOPS!
 

rrumba

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Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

no the transom is not in yet. we had a storm last night and part of the morning which made it very humid so i did not think it would be a wise idea to do anything today, then it was thundering again so i will have to wait until tomorrow.
 

oops!

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Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

ok....transom needs to go back in before the stringers or its triple the work......dont worry about the x dimension till all the glass is cured and the deck is in.

we can help you with that as well. its not that tough.

i would suggest you finish cutting the transom....and glass/laminate the new transom togeather....then shape it to fit the hull.

after the transom is built.....and dry fit.....you can work on your clamping system before you actually do the install......

after the transom is installed.....you can add the peanut butter to the lower edges and up the sides while waiting for cure......it will cure in 4 hours....then you can take the clamps off.
 

rrumba

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Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

the transom has been cut out, shaped and dry fitted. i just need to coat it with a coat of poly, then the second coat will be with 1.5oz CSM between the two sheets and the three clampled together. once that is done i plan to coat the piece that will go against the skin with it's second coat and CSM then installing it into it's new home. Does that sound right? for clamping it i will probably have to drill holes at the bottom so i can use threaded rods to clamp it then fill in th holes with poly
 

oops!

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Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

one thing i do......is to dry fit the transom about 5 times before i glass it in.....this includes putting the major clamps in.....

this is a really important step....if you mess up...there will be gaps between the glass shell and the actual new transom....that means failure.

when the transom is built...and you have dry fitted the transom with out moving it once its in place. and confident you can install the new transom without disturbing the wet glass on both the transom and the outer glass shell........

resin coat the inside of the new transom...the area where it will contact the hull....set that aside for a second...let the resin seep into the wood....but DO NOT LET IT GET HARD.
just wait till it tacks.

when you are waiting for the resin to tack...
take a thin creamy mix of peanut butter .....and screed it on the hull...(transom area) this will take out any low spots left from grinding.
then glass the transom right over the wet peanut butter using csm.

so now we have our peanut butter on the skin...it has a layer of csm over the transom.....and the new transom is getting tacky...on the interface area.

now glass the transom with a layer of csm...right over the tacky resin....add new resin....dont worry if the resin slops over the transom....just glass it fast...the hull area will now be getting tacky..........now that the transom is glassed..install it....

dont move the new glass around......just set it in and get your clamps on.

if you are using a drill thru method like i did.....you need to cut the fiberglass so the bolts can go thru the transom but not disturbe the wet fiberglass.

also....dip the bolts in PVA so they wont be stuck in your new transom !

when the transom is being squeezed to the hull.....you will see excess resin squeezing out of the edges......this resin should be uniform...do not leave any space between the hull and the new transom.
 

rrumba

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Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

What type of wax do you add to the Gelcoat or last poly coating? i have a piece of wood i need to seal up for the flying bridge floor on my other boat that i want to do at the same time that i am sealing the other pieces of plywood today. West Marine only has PVA, is that the right stuff to add? Have not been able to find it on a search, it keeps coming back wth no results found.
 

oops!

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Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

any local fiberglass shop will have AIRDRY....it is liquid wax
 

rrumba

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Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

problem is no one around here knows what i am talking about or are very helpful as they want you to come to them. So i guess i will have to order it online. what is the mix ratio, is one 60ml bottle enough for say a QT of resin?
 

rrumba

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Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

got the liquid wax part resolved and it's on it's way now. the Cabosil and chopped fibers just got delivered. hopefully the rain will stay away and i can get things sealed, glued together and installed this week.

One of hte questions i had was instead of making a "T" type stringer like what was installed originally, i was thinking of making the stringers out of (2) 3/4" pieces of plywood, (1) 3/4" and (1) 1/2" or (2) 1/2" pieces. Which makes more sense.

Also for the deck i think i am going to go with a 3/4" instead of hte 1/2" that was orginally installed.

I have been using Auraco AC plywood, like it with the extra layers of ply even in the 1/2" and HD has it on sale for 18.88 for 1/2" and 24.57 for the 3/4", Lowes will even match the price.
 

rrumba

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Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

Ok, new update.....finally

I have been adjusting the new transom to fit as suggested. But now i have found a problem, or should i say a challenge. now that it is fit and trimmed and there is a gap all around the new transom what i have found is that due to the curve in the transom right at the top of the new transom height, there is about 4" of a gap on each side between the skin and the transom. now i know what they did in the factory. instead of making everythiing fit right, they just filled in the gaps with something that turned to powder after 40+ years.

My concern is if i follow the same method they did will it be a problem for strength with a new sterndrive as it appears that it was not a problem for a stringer drive. The other thing is what is the best route to deal with this? my thought was to install it just as planned except load up the two top corners with excess PB before mating the two surfaces and putting the clamps to it. The other thought was to install it then use a cake decorating bag and squeeze the PB with chopped strand fibers down into the gap and then fillet it. Does either one make a difference or is there a better way of doing this?

Here are some pics:

The new transom fitted and ready for the next step.

P6011231.jpg



Gaps on the port side and bottom

P6011233.jpg


P6011236.jpg




Stbd gaps and bottom

P6011235.jpg



P6011237.jpg




Top Port side

P6011221.jpg
 

rrumba

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Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

Part 2 of the pictures

here is where you can see the gaps at the top betweent the skin and new transom the are both just about the same depth.



Top Stbd side

P6011226.jpg




Top Port side

P6011221.jpg





Stick used to measure depth

P6011227.jpg




Depth the stick goes down it is the one at the 4" mark

P6011228.jpg






Could really use some help with this one.

I am headed to HD right now for more plywood and supplies so i can bolt the transom in place and get my stringers made up. back in a few.
 

rrumba

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Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

can someone help me out here as i will be getting everything ready for install later today and installing the transom, stringers and bulkeads and hopefully the front 3/4 of the floor this weekend.
 

oops!

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Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

thanks for the pm with this link.....there is so much going on in the forum that i have a hard time keeping up with all the progress.

gaps like that are common......while some will be taken up by the transom being bolted to the skin...some wont...
at this time.....you are only worried about the actual interface of the transom/skin on the aft of the boat......do not be concerened with the edges...just the flat face to face bonding....no gaps allowed.

the good thing is that you can identify the areas....

do a dry bolt up to the skin......thats right...bolt your transom on dry....then look from the outside and see if you are warping your skin. if you are....relax the bolts till there is no warpage....everything is flat and straight.

now...re measure the gaps......if the gap is more than a 1/4 inch......try to measure the depth as best you can. and mark on the inner skin what areas they are. and how thick.

a extra layer of csm or 1708 right across that area will eat those gaps up no problem....

so....at the top of the transom.....you might have an area where the skin pulls away from the wood.....that is 4 ins deep getting worse near the top.

as discussed earlier in a standard transom instlation. you add csm to the skin as well as the transom...this glass is wet on wet.

ON THE SKIN SIDE....add another layer of csm in the void areas...this strip might be 4 inches deep running the width of the transom......then possibly a strip of 1708 at 3 ins down from the top and across the width...with another layer of csm at one inch.

basically....fill the gaps with fiberglass.

a few things to watch for..... use less mekp for thicker glass applications......for instance....with this layup you have 5 layers of glass between the wood and skin...so you will want to catylize colder....try 1.7 percent.
the other thing....is wait a minit or two after you glass the skin and transom till the install....not 5 mins...just a minit or two.....the glass will want to slide with more layers...so take extra care when installing the transom....you cant have the glass bunch up causing an air void or un even surface between the wood and the skin.

this is where your dry fitting practice comes in.....you have to be profecent with fitting it and know you can do it with out moving the glass on the wood or the skin....the glass will be wet...the styrene will break down the csm...and it will want to move easily.....getting the transom in with out twisting on it is crutial.

....now....the gaps around the edge are filled with peanut butter......after the transom is bolted in....and curing......take a putty knife and push peanut butter as far into the gaps as you can.....you want to fill the gaps totally (or as best you can) this will take a lot of peanut butter...so work in small batches or the stuff will cure in the bucket on you. do not add peanut butter to the bottom first and set the transom on it.....add the pb after.
 

oops!

Supreme Mariner
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Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

problem is no one around here knows what i am talking about or are very helpful as they want you to come to them. So i guess i will have to order it online. what is the mix ratio, is one 60ml bottle enough for say a QT of resin?

60 mils is lots of wax......
it is mixed at 3=5% of resin.....5% for heavy areas.......this is double the amount of mekp....and you only use drops of that.

.and sorry......any body that sells fiberglass and resin....and does not know what wax (or airdry) is.....has never used the product.....this is a clue no to take their instructions on how to use it.
 

rrumba

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Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

60 mils is lots of wax.......and sorry......any body that sells fiberglass and resin....and does not know what wax (or airdry) is.....has never used the product.....this is a clue no to take thier instructions on how to use it.

yeah that was my thought as well, to stay away from them and keep on walking. i plan on using it for the last coat of gelcoat on the entire boat as well. hopefully the 60mil will be enough as i have not found out the ratio to add per qt yet. i plan to spray the gelcoat.
 

oops!

Supreme Mariner
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Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

what is the mix ratio, is one 60ml bottle enough for say a QT of resin?

i highly suggest that anyone mixing fiberglass resin...mekp or wax use the metric system,,,,if you can count to 10...you can figgure out this system....forget qts...pints and at what percent you cat a pint....

if you use the metric system...it is childs play....if you mix 100 ml of resin....(it is marked on the mixing pail)....you measure 2 ml of mekp.....2% of 100 is 2. its that easy.
 

oops!

Supreme Mariner
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Messages
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Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

ok....i think i got all your questions....ill be on and off all day....if i missed a question...just pm me again and ill get right to it.

cheers
oops
 

rrumba

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Messages
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Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

thanks for the pm with this link.....there is so much going on in the forum that i have a hard time keeping up with all the progress.

gaps like that are common......while some will be taken up by the transom being bolted to the skin...some wont...
at this time.....you are only worried about the actual interface of the transom/skin on the aft of the boat......do not be concerened with the edges...just the flat face to face bonding....no gaps allowed.

the good thing is that you can identify the areas....

do a dry bolt up to the skin......thats right...bolt your transom on dry....then look from the outside and see if you are warping your skin. if you are....relax the bolts till there is no warpage....everything is flat and straight.

now...re measure the gaps......if the gap is more than a 1/4 inch......try to measure the depth as best you can. and mark on the inner skin what areas they are. and how thick.

a extra layer of csm or 1708 right across that area will eat those gaps up no problem....

so....at the top of the transom.....you might have an area where the skin pulls away from the wood.....that is 4 ins deep getting worse near the top.

as discussed earlier in a standard transom instlation. you add csm to the skin as well as the transom...this glass is wet on wet.

ON THE SKIN SIDE....add another layer of csm in the void areas...this strip might be 4 inches deep running the width of the transom......then possibly a strip of 1708 at 3 ins down from the top and across the width...with another layer of csm at one inch.

basically....fill the gaps with fiberglass.

a few things to watch for..... use less mekp for thicker glass applications......for instance....with this layup you have 5 layers of glass between the wood and skin...so you will want to catylize colder....try 1.7 percent.
the other thing....is wait a minit or two after you glass the skin and transom till the install....not 5 mins...just a minit or two.....the glass will want to slide with more layers...so take extra care when installing the transom....you cant have the glass bunch up causing an air void or un even surface between the wood and the skin.

this is where your dry fitting practice comes in.....you have to be profecent with fitting it and know you can do it with out moving the glass on the wood or the skin....the glass will be wet...the styrene will break down the csm...and it will want to move easily.....getting the transom in with out twisting on it is crutial.

....now....the gaps around the edge are filled with peanut butter......after the transom is bolted in....and curing......take a putty knife and push peanut butter as far into the gaps as you can.....you want to fill the gaps totally (or as best you can) this will take a lot of peanut butter...so work in small batches or the stuff will cure in the bucket on you. do not add peanut butter to the bottom first and set the transom on it.....add the pb after.

Thanks alot.

so would it be better, once i have dry fitted the transom as described, to build up the area on the SKIN SIDE with the layer of CSM, then once tacked, fit the transom again and check, then if needed, do the layer of either 1708 or CSM, then fit again, or just try and measure as close as possible with the dry fit and then do the build up, then the CSM on the transom and once both tack mate them together?

Once i have the transom in place and bolted, i should wait about 4 hours before removing the clamps? then i can start the stringer installs? I kind of like the idea of a faster set time using the PB for filleting and not using the PL at all for it so I do not have to wait the 24 hours before moving onto the stringer install.

once the clamps are off i can start the PB install around the transom or can i do it at the same time?
 

rrumba

Ensign
Joined
May 31, 2011
Messages
901
Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

Re: 1967 IMP Aztec -- Thoughts and suggestions for Rebuild maybe repower

i highly suggest that anyone mixing fiberglass resin...mekp or wax use the metric system,,,,if you can count to 10...you can figgure out this system....forget qts...pints and at what percent you cat a pint....

if you use the metric system...it is childs play....if you mix 100 ml of resin....(it is marked on the mixing pail)....you measure 2 ml of mekp.....2% of 100 is 2. its that easy.

so the mix ratio is 2% by volume then, and it is based on the resin and not the resin and wax combined, but just the resin. Same would be true for the PB mix then as well, however much resin i have in the pot, say 100ml, it will be 2ml of MEKP, after i have added the chopped fiber strands and cabosil

thanks again
 
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