80's Arrowbolt 21 'Project'!

[Ed]

Sounds good. Just get it chopped out and cleaned up and go from there!

[Capn Jack]

You know, that engine has been out and repainted, plus those manifolds look like they have been replaced along with the risers and elbows.


What I would say is this and to which you may already be an expert in, but........dry out all the wood before you apply any resins/glass, even Epoxy resin will not stick to wet wood.

ABSOLUTELY, DO NOT USE polyester or vinylester resins. Only use epoxy. Even though the boat is made from POLYESTER resins, when built, these would not have cured before other resin layers were added. Epoxy is the only resin today which will stick mechanically to wood and any other glass/resin combination.

[Ed]

Whilst I don't want to disagree with Capn, having now done a ton of repairs with both Epoxy and Polyester, for the majority of this one I'd use Poly, the cost of doing all that in Epoxy would be immense, good decent prep and it will all be fine except for perhaps the heaviest load bearing parts.

Just make sure you grind to fresh glass, and its cleaned with acetone and I'm quite sure it will be absolutely fine. Engine mounts and transom structural points I'd use epoxy but for everything else now I'd use Polyester.

Just IMHO!!

[Capn Jack]

In as much as I hear what you are saying Ed and I accept that I appear to be an old stick in the mud full of ancient remidies, I have also said many a time that water get's into fibre glass boats and rots them and been shot down in flames for saying it. This in turn may have put me down as being a mere fantasist, however, this latest post and your topics regarding rot have proved me right.

This therefore may not be proof that Polyester resins will stick to wood and cured Polyester, however I know that Epoxy is the only resin to stick with any meaning to other resins, which have cured, or wood.

I suppose if it's only cosmetic repair then polyester will do, but for structural, Epoxy every time.

[Ed]

Accepted! Just my own experience with my repairs (especially on the blue boat) before I even knew about epoxy were fairly structural in the fact you stood on them etc, were all done with polyester and after a year of good beatings were entirely unaffected. The luxury of epoxy at £5x is hard to justify for non critical areas when for me at least a good decent job with polyester that has for me held up fine.

Even the boat repair book I have says that for most jobs polyester will do the job if the work is carried out correctly:)

[rbcoomer]

Thanks for the all the advice on the resins - this is indeed an interesting topic! I've done quite a bit of research on this and spoken to a couple of local guys who do this professionally - there seems no doubt that epoxy is a safer option...

BUT... I have two hurdles. The first is cost - I'm already looking at perhaps £600-800 for glasswork. The second is unknown ability - not having done this before there seems little doubt that epoxy is going to be more sensitive to time and conditions. The polyester allows a greater variation in timing and conditions.

I think I've reached a compromise and this is the current plan:-
1) preparation - I'll need to have everything on hand and as mentioned best possible preparation of surfaces in terms of existing GRP keying and cleaning.
2) not to be over ambitious on first layers - small areas/quantities at a time!
3) all timber will be new, dried and prepared - I've been advised to store cut sections in the house a few days prior to using. There is a special resin preparation for wood that has been suggested to paint on first. This is thinner and soaks into the woodgrain. I'm going to do some testing on this first! Will post the details of this when I have the notes to hand as I can't remember what it's called!
4) I've been advised to use a woven glass tape and epoxy for structural joins - like transom and bulkheads - and then glass over this with the polyester before fully cured. Apparently this allows the epoxy to bond to both layers where there is any doubt about the bond? That said, the first guy who suggested this also had the view it was unnecessary for me as the boat wasn't epoxy to begin with and that it was only 'really needed' when bonding to old epoxy not old polyester. He was confident he'd go with polyester - but then added '...if you have any doubts...' Suffice to say that fueled the doubts rather than allay them!
5) no shortcuts or rushing... Although I'm obviously 'very keen' (understatement!) to get her on the water, I can't seen the point in putting in anything less than 100% and taking the time to do the best job I can.

I've also kept all the large sections of removed fibreglass and will be doing some testing of bonding of various methods before I start.

The engine was said to have been rebuilt a few years ago and the drive replaced. This certainly appears to be the case and the drive is an AlphaOne not the original VP sterndrive...

[markanddawn]

I am impressed with your enthusiasm and ability. Atleast you have another boat to use, while working on this one. What a great idea, something to use when the weather permits and still working with boats when it is less than ideal, although I guess you will need some nice weather for the project too.

Regarding the outdrive, you will be surpised how well it will clean up. Look at my before and after. From memory, I think it was International's outdrive antifoul. It was supposed to be black (as per aerosol cap and can) but came out grey but did the job and you can't see it anyway when in the water really, well not by us as the water is brown, except the marina which is fresh water.

[Capn Jack]

Another techy post from Mark...........

[jokaboat]

No Mark's not a techy, probably Dawn

[markanddawn]

No Mark's not a techy, probably Dawn

Oh Joka, you will not believe how true that is, seriously I do nickname her Dave, when she gets carried away

[Matt13]

Yeah you need to reign it in a bit Mark, your making me look bad thought we were supposed to stick together

[rbcoomer]

Interim update...

Slow progress currently due to work, getting ready for June rally and really need to lift engine out now. Suspect progress will halt a while soon whilst I source and rig a lifting mechanism!

Most engine ancilliaries now removed - transom sheild, steering etc next...
[img]http:swfbr.org.uk/rbc/engine_bay_may12.jpg[/img]

I have been cutting back the tabbing (hand pointer) and stringers (arrowed)


Exposing the engine bay end of stringers



Engine bay floor



Engine bearers

[Gazjen]

Amazing keep up the good work!

Great determination, I know absolutely nothing about epoxys and glassing so your task would really worry me.

You should be proud that you are bringing that boat back to life, that otherwise would have been left to rot and be forgotten

[rbcoomer]

Hi Gaz,

Me neither on the fibeglass front! However I've done car bodywork with both plastic & fibreglass so not completely 'green'...

I have taken the precaution of keeping many of the removed sections so will do some practice and bond testing before I start. I'm going with polyester because of costs and amounts required and there seems to be debate/differing views on 'stickability' - especially bonding to old hull layups.

The original fibreglass sections vary in thickness between 2-5mm so I'm aiming for around 3-4mm - probably 3 layers with 300gsm? (tests will establish this I hope) I aim to treat all the timber first with SP Eposeal 300 (http://www.mbfg.co.uk/epoxy-resins/epos ... rimer.html) this should seal the wood and provide a good, clean surface. Although they state it provides an excellent bonding surface for epoxy, they don't mention polyester - hence lots of testing first! If it works, I will also prep the existing GRP hull with it too (after a good clean). If all else fails, I will need to tab in stringers, bulkheads etc with epoxy first and then overlay with polyester. Unfortunately, the cost of doing all the form work with epoxy resin would just be too high - I suspect the glasswork is already going to be in the region of £600-800 plus similar for the wood!

I'm looking forward to getting started, but there's quite a bit still to do before that stage.

[Capn Jack]

I've just written a post you may have found interesting and lost the lot, internet connection...... Unfortunately I've run out of time to rewrite, got to go to work.

However, it was about these article etc. you may find them interesting, the first one I found 10yrs ago for a similar project, the second you may find helpful.

About the Sealer/Primer, it should work but try laminating the Polyester Resin/Glass mat whilst it is still tacky, you should then get a good chemical bond.

If you are going to try a test on the old wood make sure it's dry otherwise your test may be inconclusive.

Rot Doctor

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