70's era 15' Yarcraft yankee project question

[oba97]

I have been doing a lot of research in prep for my project boat. I know the floor is bad but not sure on the transom and stringers? The boat is 2hrs away at my inlaws (I am picking up this weekend). I assume I will need to do a complete rebuild. I feel like I have a good handle on what I will need to do but I keep going back and fourth on Poly or Epoxy???? It seems like everyone has their own personal opinion and both will probably be ok? I know that I will be putting more money and time into the boat than it is worth but I told my inlaws I would get it water ready (they said if I do I can have it) and I like to work on projects. I guess my question is.... will poly be ok for this project? I would like to keep cost down but not at the expense of safety. Im also not looking to get another 10 years out of the boat...I figure in a few years I'll be looking for a new one.

 

[Woodonglass]

Welcome to iBoats!

The boat is made from Poly. If you prep it correctly you'll be perfectly fine using Poly to restore it. If you can find Poly reasonably close to you then it's cheaper but ...since it's classified as a hazardous material, shipping IS quite expensive and can be prohibitive. Epoxy costs more but shipping is less. Epoxy, to me, is a bit harder to work with due to extended drying times but it is also stronger and a better adhesive so you don't have to be quite as careful in your prep. It's totally up to you and the difference in costs will be a few hundred dollars.

 

[gm280]

Welcome to iBoats!

The boat is made from Poly. If you prep it correctly you'll be perfectly fine using Poly to restore it. If you can find Poly reasonably close to you then it's cheaper but ...since it's classified as a hazardous material, shipping IS quite expensive and can be prohibitive. Epoxy costs more but shipping is less. Epoxy, to me, is a bit harder to work with due to extended drying times but it is also stronger and a better adhesive so you don't have to be quite as careful in your prep. It's totally up to you and the difference in costs will be a few hundred dollars.

I also can tell you that the hazmat fee for ONE five gallon bucket of polyester resin is $26.00 per. And that isn't the shipping cost either. So factor in that if you have to have it shipped. And that brings me to wonder. Since I haven't ever heard of any such problems with shipping polyester resin in the news, why keep adding such fees on every bucket? I mean where does that money go and why? Seems a real money making scheme to me. I mean think about all the hazmat fees applied to shipping cost every day of the week all across this country. And then think about how many issues actually happen to cause any problem. I haven't seen even one in the news... Ranting off now... :facepalm:

 

[oba97]

I would have never thought there would be extra shipping charges on top of the regular. I guess if I'm going to use poly I should try and find some local.

 

[Woodonglass]

Make sure you get the right kind of Poly. You need Laminating UNWAXED Resin. All the stuff sold in the Auto Parts stores and the Home stores has wax in it and you DON'T want that .

 

[DeepBlue2010]

If you want a good compromise between poly and epoxy, use vinyl ester resin. Ask your local supplier if they carry it. The price difference between regular laminating resin and vinyl ester resin is not that much (relative to epoxy) but the quality of the resin is well worth it.This is the only resin I use.

The problem with HomeDepot and auto stores resins is not the wax. Wax is ok, actually preferable, if you will finish glassing an area in one session. The problem with these resins is they are hard to work with as they tend to gel much faster. I am not sure if they were formulated differently to take the longer shelf life or what.

 

[oba97]

I plan on working on this during the winter months here in Michigan. Is there a min temp that my garage should be before I can glass using poly? if so how long does it need to stay at that temp? I have an electric heater that will keep it in the 60's (havent tried to keep it warmer) when the temps are in the single digets outside. But being electric it will kill me in bills if I need it that warm for days. Can I do this if my garage temps are ~40 (roughly what my garage is without heat)?

 

[Woodonglass]

The problem with HomeDepot and auto stores resins is not the wax. Wax is ok, actually preferable, if you will finish glassing an area in one session. The problem with these resins is they are hard to work with as they tend to gel much faster. I am not sure if they were formulated differently to take the longer shelf life or what.

Not sure I understand or agree with this but I'll wait to see your explanation as to the why???

 

[DeepBlue2010]

We do add wax - deliberately - to the final layer to ensure proper cure to the surface layer, don't we? Wax is a hassle only if the laminate will be done in multiple sessions because of the need to sand off for the next layer to adhere properly. Do I miss something?

 

[Woodonglass]

Uhmmm Wax is not required for Poly to cure. It speeds it up a bit and does make it easier to sand but it will cure just fine over time. No wax required. I never add wax except when making fairing material so I can sand it, or to the last batch used for laying the deck IF it's gunna be painted. Other than that...No wax ever!!! ondarvr says the same thing and he's been selling the stuff for over 40 years!!

 

[gm280]

Wax on, wax off...now where did I hear that before... eep:

 

[DeepBlue2010]

The laminate will cure, I did not say wax is required for the whole laminate to cure. I said " to ensure proper cure to the surface layer". The top few thousands of an inch will not cure according to resin manufacturing datasheets and literature. Sometimes this is not an issue if the laminate will be left alone (under deck structures, stringers, bulkheads, etc) but if the laminate will be finished (painted or gelcoated), the surface layer must be sanded down to a cured layer of resin if no wax or PVA were used. As we all know, sanding a gummy surface is PITA process.

I read every word Ondarvr says very carefully and I don't think he called for never use wax as in never use any air isolation technique if subsequent finishing is required. I remember vividly he said even using PVA is fine if the use of wax is not desirable for whatever reason. So, any way you cut it, I don't think my statement was wrong. If you - on the other hand - don't do that and it works for you, that is a different story.

 

[Woodonglass]

Yes, but there's no need to have wax in the underlying laminates and it can be detrimental to them even if done wet on wet. It's still in the mix and if the temps are high it will float to the top pretty quick and interfere with the next layer. I personally would not say it's preferred when doing any laminations other than the final layer when a painted surface was anticipated. It's Ok for the Last mix as you and I both previously stated, That's why it's called "Finishing" resin as opposed to "Laminating" resin. By the way not speaking for ondarvr but..http://forums.iboats.com/forum/boat-...s#post4763630;) Post #2

 

[oba97]

While reading I came across a post from 08. It talked about tri-hulls having a strong hull by nature of design and on small boats instead of replacing stringers you can just put a new deck down, drill weep/pour holes and pour 4lb poly foam to fill all voids. Per that post they say it is stronger than origional. Is this true? I cant say I have heard much about that in all my reading so Captin Obvious would say it's not a great option I guess??

 

[DeepBlue2010]

Getting a definitive answer for the questions of better or stronger than the original requires a computer modeling and/or field testing which I am sure no one is welling to do. Anything less, it would be just pure speculation.

What I can tell you for sure is that in any commercial manufacturing facility, cost accounting makes engineers justify the hell out of every cost item before they approve it. If you found stringers there, it has been put there for a reason and it is not out of the goodness of their hearts.

I would be more comfortable returning everything to the way it was unless you are sure that your methods are the same or better or you are welling to take the risk.

 

[Woodonglass]

While reading I came across a post from 08. It talked about tri-hulls having a strong hull by nature of design and on small boats instead of replacing stringers you can just put a new deck down, drill weep/pour holes and pour 4lb poly foam to fill all voids. Per that post they say it is stronger than origional. Is this true? I cant say I have heard much about that in all my reading so Captin Obvious would say it's not a great option I guess??

There were some hulls designed to be "Stringerless" and totally foamfilled. Obviously yours was NOT one of them. I agree with DB2010 that it usually best to stick with the original design.

 

[oba97]

I plan on doing the strings but thought it was a interesting idea to ask about.

 

[Woodonglass]

Yeah, it would be nice and, Tri-Hulls do lend themselves to Foam Filling but I still think it best to stick with the original design. You could prolly fill er up and go boating and never have and issue but boy I don't think I could ever rest easy doing that!!!!!:nono:

 

[ondarvr]

I never use waxed resin, and rarely ever advise it, if you quickly need a well cured surface that is tack free, it works well, other than that it creates other possible issues and more work. That's why I say to never buy waxed resin. Most resins will become tack free rather soon on their own, or at least tack free enough for sanding with 36 grit on a grinder, which is probably the most common method of sanding the backside of a laminate. If it will be a surface that needs to be tack free, I will normally coat it after all lamination has been finished with a batch of waxed resin, it may have been 30 years ago when I last needed to do it though. There is one market segment that uses a resin finish on there parts, it's just for industrial purposes, and they do use wax in the final coat of resin.

Adding 4# foam would probably work, but it would increase the cost and probably make the finished product weigh more. The safest and lowest cost method is to just go with what was there to begin with, just do a better job of it, which isn't hard.

 

[DeepBlue2010]

Ondarvr, thanks for chiming in. If we set aside the issue of the resin itself being waxed or unwaxed, I am curious to know what are the possible issues that might develop of adding wax to the resin deliberately to ensure proper cure of the surface?

Is it the sanding and the contamination of wax that might hinder the subsequent painting or it has something to do with the structural integrity and the curing characteristics of the laminate?