HELP Transom lamination went way wrong

[gregorymacc]

Any help would be greatly appreciated. I am in the middle of redoing my 93 oceanmaster transom. I am going at it from the inside I cut out the old core and ground down the glass etc... I went to laminate my 2 pcs of 3/4" penske board and the lamination did not go well. to the point I was able to separate the two pcs. I am using vynalester resin and I was doing the lamination in the sun yesterday 105 degrees but the ambient temp was around 68 degrees. I did the following
1. paint both sides of hte core with resin.
2. resin began to kick off way quick about 10 min
3. after seeing the resin almost cured but still a bit tacky I decided to lay down 1pc of 1708 cloth on one part of the core.
4. that began to cure quicly as well I figured due to the fact that I was in the dirct sunlight
5. I then mixed up 2 batches of thicked resin I under cataylsed a bit to compesate for the heat of direct sunlight. then samwiched the two cores together and weighted it down.
6. let it sit overnight and this afternoon went and checked the laminate and noticed that there was a small void in between the two cores next thing I know I was shoving wedges into the core and separating the core.

ANy help and direct would be much appreciated. I am thinking of switching over to epoxy because of the superior bonding. Can some one talk me off the ledge?

[gofastsandman]

Get away from the contraband.

All products freshly made? if so, you may have backed off the catalyst too much.

Not to seem unwelcoming, but you have a great racehorse in Mark the builder. He loves talking about his babies. I would call him as he knows a thing or two.

Cheers,
GFS

[hermco]

You might want to glue them together with 1.5 oz. mat not 1708. Are you using a brush to apply the resin? Get a 4" roller frame from the Depot or Lowes with 9" economy semi smooth roller covers cut in half. The green ones. Much faster. Toss them when you are done glassing.

[strick]

Also dont glass in 105 degrees wait till it cools down in the evening

strick

[3rdday]

Son your not in the middle of the repair it sounds......
I would rip out the glass that did not get fully wet out, and start over.
you can refridgerate the resin before you catalyse it to slow down the reaction.
You may also want to mix smaller batches, the larger masses will accelerate the exothermic reaction exponentially.
General information as it regards to thermoset resins;
For every 20 degree increase in temp the pot life/work time is cut in half and its exponential for every 20 degree increase typically the relative temp referenced is 72-77F
The reverse is true for every 20 degree decrease in temp the pot life work time is increased, it is exponential as well.

Originally Posted by gregorymacc

Any help would be greatly appreciated. I am in the middle of redoing my 93 oceanmaster transom. I am going at it from the inside I cut out the old core and ground down the glass etc... I went to laminate my 2 pcs of 3/4" penske board and the lamination did not go well. to the point I was able to separate the two pcs. I am using vynalester resin and I was doing the lamination in the sun yesterday 105 degrees but the ambient temp was around 68 degrees. I did the following
1. paint both sides of hte core with resin.
2. resin began to kick off way quick about 10 min
3. after seeing the resin almost cured but still a bit tacky I decided to lay down 1pc of 1708 cloth on one part of the core.
4. that began to cure quicly as well I figured due to the fact that I was in the dirct sunlight
5. I then mixed up 2 batches of thicked resin I under cataylsed a bit to compesate for the heat of direct sunlight. then samwiched the two cores together and weighted it down.
6. let it sit overnight and this afternoon went and checked the laminate and noticed that there was a small void in between the two cores next thing I know I was shoving wedges into the core and separating the core.

ANy help and direct would be much appreciated. I am thinking of switching over to epoxy because of the superior bonding. Can some one talk me off the ledge?

[martin]

Although i have not used that type of core. I have used corecell and nidacore.. When Laminating I always make a couple of test batches of resin about 4 oz at a time and then with a a measured amount of catalyst.. kick them off and time them. That way you get an idea on how much to use. and if you are doing a large area like transome. i always lay out my resins measured and with catalyse measured that way you don't waste time pouring and measuring..As far as the laminate always use mat aganst the board then 17oz or 18 oz biaxial or roving then mat again for the other side.. of the laminate. The mat adhearse better to the parts.but the biaxial gives the strength as you probably know already.. oh and I always mix my last batch abit cold cause of the other batches generate heat and I do not want to create air or gas in between cores. and never glass in direct sunlight. .

[bly]

sides of the 1708. I know that putting glass in-between cores is a very good way to make a core even better. That is a fact. Te problem is that you were not set up to do the job in a timely manner. I prefer vinyl ester resin over epoxy because of viscosity also. Especially over west system epoxy. get everything layer out properly for speed of process. Rollers are a good choice as said in a post. . I use rollers all the time on wetting out glass. I like the thin diameter 6 inch ones at home depot..You have to stay wet also. Dry laminates are a problem. Then you should have a clamping system to squash everything tight. This should all be done dry more then once before the real wet lay up. Again the 1708 was a good idea to make your cores even stiffer. Look at how stiff the coosa is with the glass in the foam.

[gregorymacc]

Gentlemen,
thanks for the replys this is not the first time i have glassed but the first time I have used an ester resin i gennerally used epoxy and was able to do my glassing in a controlled environment. I was trying to rush and get the job done rather than laying out the job first. I became a victim of get the boat done and in the water rather than doing a thorough job. I have since cleaned and ground down my penske core and will again attempt to relaminate. my schedule will be to 1st skim coat core with some thickened resin to fill in the low spots from grinding then I will place layer of 1.5oz matt on both sides let that set up then add a layer of 1708 let that tack up then use thickened resin to set the core and use screws every 8" to clamp then let it sit for 2 days.